September 19, 2026 • 43 mins
This 2021 episode covers smallpox, a viral disease that has existed for millennia. But it’s now one of only two diseases that’s been eradicated through human activity, and a global plan was enacted to do it.
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Speaker 1 (00:02):
Happy Saturday.
Speaker 2 (00:03):
Since we mentioned our episode on the eradication of smallpox
this week, we are bringing it out as today's Saturday classic.
At the end of this episode, we mentioned guinea worm disease,
also called draconchioliasis, as a disease that could potentially be eradicated.
According to the World Health Organization, in 2025, there were
(00:23):
10 reported cases of draconchioliasis. There were 15 in 2024,
14 in 2023, and.
Speaker 1 (00:33):
13 in 2022.
Speaker 2 (00:34):
This episode originally came out September 1st, 2021. Enjoy!
Speaker 1 (00:41):
Welcome to Stuff You Missed in History Class, a production
of iHeartRadio.
Speaker 2 (00:51):
Hello and welcome to the podcast. I'm Tracy V.
Speaker 1 (00:54):
Wilson. And I'm Holly Frey.
Speaker 2 (00:57):
Late March of last year, I researched and wrote our
episode on the eradication of render pests. Because in that moment,
it just felt really weird to me to work on
episodes that were not about the pandemic somehow. Because that
was dominating everything in our lives. But at the same time,
I wanted to work on something that felt kind of optimistic.
(01:20):
Because the pandemic was dominating our lives. So now it's
almost a year and a half later. Here in the U.S.,
we had a pretty hopeful springtime regarding the progress of
the pandemic. I know that was not the case in
the whole world, but we had what was looking like
improved situations. That obviously has taken a turn once again
(01:45):
for the worst, or at least the worst, maybe not
the worst of ever, but definitely worse. I wanted to
kind of return to the idea of wiping a disease
off the face of the earth. So, rinderpest and smallpox
are the only two diseases that have been eradicated through
human activity. Neither one of them is technically extinct because
(02:07):
there are some samples of both viruses that still exist
in labs. They're no longer circulating out in the wild, though.
And we've talked about smallpox a bit on the show before.
We had our episode on Edward Jenner and the smallpox
vaccine and how the vaccine was developed and then Jenner's
efforts to try.
Speaker 1 (02:24):
To make it more widely available.
Speaker 2 (02:27):
More recently, we did the episode on the Royal Philanthropic
Vaccine Expedition, and that was all about Spain's efforts to
transport the smallpox vaccine to the Americas, which required a
chain of living human hosts.
Speaker 1 (02:41):
We mentioned.
Speaker 2 (02:42):
pretty briefly, the eradication of smallpox in both of those episodes,
but we have not gone into detail about how that happened.
That's what we're going to talk about today. And when
Tracy mentioned it to me, I said, we've covered that.
Speaker 1 (02:58):
Nope. It just keeps coming up. It just keeps coming up.
Speaker 2 (03:01):
We've said in like a sentence how it was done,
but it's more than a sentence worth of explanation. Yeah. Yeah.
Speaker 1 (03:08):
It's just, it's been... just peppered in enough that my
brain was like, yeah, that was an episode, right? Nope. Nope.
So smallpox is a viral disease that has existed for millennia.
When it was circulating in the wild, it spread from
person to person through the air, usually through face-to-face contact,
and it can also be spread through contact with contaminated
(03:30):
objects and surfaces. People who contracted smallpox typically developed a
high fever and body aches, and that was followed by
a distinctive rash. There are two different strains of the
variola virus that were causing smallpox, variola major and variola minor.
As that name suggests, variola major caused more serious illnesses.
(03:52):
As many as a third of people who were infected
with variola major died. As many as 90% of babies died.
Speaker 2 (04:00):
It was also particularly lethal anytime it was introduced somewhere
that it hadn't existed before, such as when Europeans started
arriving in the Americas. And in those cases, smallpox usually
killed about half the people who contracted it. Among the
people who survived the disease, smallpox could also be both
disabling and disfiguring.
Speaker 1 (04:21):
There was and is no cure for smallpox. So even
as science and medicine progressed, it continued to be deadly.
but it also had some traits that made it a
good candidate for a worldwide eradication campaign. Smallpox was easy
to recognize and diagnose, unlike, say, the flu, which can
resemble a lot of other respiratory infections. Smallpox passed directly
(04:45):
from person to person and only infected humans, so there
were no hidden reservoirs of the virus that could potentially
start a new outbreak. That's different from something like yellow fever,
which also infects other primates, and is transmitted by mosquitoes.
Another plus, once a person had recovered from smallpox, they
were immune for life. For a number of reasons, smallpox
(05:10):
outbreaks also tended to develop relatively slowly. Once people were contagious,
they were usually also too sick to really leave home,
so outbreaks tended to cluster around members of the same
household and their immediate neighborhood. And then once an outbreak
was identified, swift action could keep it from spreading very far.
(05:30):
And most importantly, there was a way to disrupt transmission
of the disease, in this case, a vaccine. In terms
of the smallpox vaccine, at first, people prevented smallpox using
a technique called variolation that involved intentionally introducing material from
one person's smallpox sore or scab into another person. Practitioners
(05:52):
in Asia were doing this as early as the 11th century,
and the technique spread from there. Then, in the late
18th century, people started to make a connection between smallpox
and another much milder disease that was called cowpox. The
smallpox and cowpox viruses are both in the genus Orthopoxvirus,
and people who had contracted cowpox seemed immune to smallpox.
(06:16):
Several people, including Edward Jenner, tried deliberately exposing people to cowpox,
as a way to prevent smallpox. Jenner called this vaccination
after the Latin word for cow.
Speaker 2 (06:28):
So both variolation and vaccination could prevent smallpox, but since
variolation could also cause full-blown smallpox, vaccination was a lot safer.
At the same time, though, vaccination in its earliest forms
carried some of the same risks that variolation did, including
the potential for transmitting other illnesses like syphilis and hepatitis
(06:51):
from person to person during these person-to-person vaccination chains. Sometime
in the 19th century, people shifted from using cowpox to
using vaccinia virus, which is another orthopox virus, to make
smallpox vaccine. The origins of the vaccinia virus are unclear.
It is possible that it's actually some kind of hybrid
(07:12):
of cowpox and and smallpox, or that it developed over
time as cowpox virus was passed through multiple hosts in
the process of making vaccines. Eventually, vaccinia virus replaced cowpox
virus for vaccination purposes, just as vaccination with cowpox had
previously replaced variolation with smallpox itself. At first, vaccines made
(07:36):
with vaccinia virus were grown in the skin of live
animals like calves, sheep, and rabbits. Eventually, that shifted to
growing the virus in tissue cultures or in chicken eggs.
These methods replaced those arm-to-arm vaccination chains that we talked
about in our episode on the Royal Philanthropic Vaccine Expedition.
(07:57):
Countries actually started to outlaw arm-to-arm vaccinations in the late
19th century. Many of the vaccinia strains used to make
vaccines were attenuated or weakened by repeatedly passing them through
a non-human host. things like chick embryo cells, eggs, or mice.
This process resulted in a virus that produced an immune
(08:18):
response when a person was vaccinated with it, but couldn't
reproduce in that person's body and make them sick. So
while vaccination with cowpox virus was safer than variolation with
smallpox virus, vaccination with an attenuated version of vaccinia virus
was also safer than vaccination with live, unattenuated cowpox. Yeah,
(08:39):
there were still potentials for various complications, but this was
an improvement overall. It really didn't take long after the
development of vaccines for people to wonder whether vaccines could
be used to eliminate smallpox entirely. But early attempts to
do this faced a lot of obstacles. As we talked
(08:59):
about in our episode on the Royal Philanthropic Vaccine Expedition,
early versions of smallpox vaccine lost their potency really quickly,
especially in hot weather. And that continued to be true
after vaccinia replaced cowpox as the preferred virus for smallpox vaccines.
But then in the 1940s, people started working on dehydrated
(09:21):
and freeze-dried versions of the vaccine. The Vaccine Institute in
Paris produced a freeze-dried, vacuum-packed vaccine that had a longer
shelf life. In the 1950s, Leslie Harold Collier at the
Lister Institute studied the preservation methods that were in use
and how effective they were, and he developed a process
that didn't require refrigeration, even in tropical temperatures. Once the
(09:45):
vaccine was reconstituted, it still had a short shelf life,
but until that point, it could survive in the field
for months. It also protected people from smallpox infection for
at least 10 years and offered protection against dying of
smallpox for some time after that. Collier's method eventually became
the World Health Organization standard for vaccine used for the
(10:07):
eradication campaign. Smallpox was eliminated in North America in 1952
and in Europe in 1953. And that was done primarily
through mass vaccination campaigns, especially ones that were done in
response to outbreaks. And this success came in spite of
increasing resistance to vaccines and to compulsory vaccine programs. In
(10:30):
the United States, this resistance led to a Supreme Court
case in 1905, The city of Cambridge, Massachusetts, had been
trying to stop a smallpox outbreak and had ordered all
adults to be vaccinated or to pay a $ 5 fine.
Henning Jacobson refused to be vaccinated, and then after being fined,
he took the matter to court. In the words of
(10:52):
the court's decision, quote, the liberty secured by the Constitution
of the United States does not import an absolute right
in each person to be at all times and in
all circumstances wholly freed from restraint. nor is it an
element in such liberty that one person or a minority
of persons residing in any community and enjoying the benefits
(11:13):
of local government should have power to dominate the majority
when supported in their action by the authority of the state.
It is within the police power of a state to
enact a compulsory vaccination law, and it is for the
legislature and not for the courts to determine in the
first instance whether vaccination is or is not the best
mode for the prevention of smallpox, and the protection of
(11:36):
the public health. We'll get some more on the campaign
to eradicate smallpox in the rest of the world after
a sponsor break. The World Health Organization's decision-making body is
(11:56):
called the World Health Assembly. And in 1953, the WHA
didn't consider smallpox to be a candidate for global eradication.
It just wasn't a priority. But five years later, a
delegate to the WHA proposed a 10-year eradication plan. That
delegate was Professor Viktor Zhdanov, who was deputy health minister
(12:18):
of the Soviet Union. And this proposal included vaccine donations
that would be provided by the USSR. But even with
the promise of donated vaccines, this proposal still didn't pass.
At the time, the World Health Organization was working on
an anti-malaria program, and that was really just drawing most
of the focus. In 1959, the Soviet Union's proposal was reintroduced,
(12:42):
and this time it was passed as a voluntary global
vaccine campaign. Countries where smallpox was endemic, that is, freely circulating,
were asked to institute mass vaccine programs with a goal
of vaccinating 80% of their populations. And the countries where
it wasn't, which were generally richer, were asked to contribute
(13:02):
funding or vaccines toward the effort. At that point, smallpox
was being reported in 63 countries, and together those countries
reported 77,555 cases of the disease. but it became obvious
really fast that that number was way, way too low.
For one thing, those 63 countries only included the ones
(13:26):
that were members of the World Health Organization, and some
countries where smallpox was endemic were not members at that point,
and that included China, which had a population of more
than 660 million people. But even in those 63 countries,
reporting was all over the place. In countries without a
lot of public health infrastructure, smallpox cases weren't really being tracked.
(13:48):
But even in places where that wasn't the case, sometimes
the only smallpox infections being reported were the ones that
ended up in hospitals. In reality, the countries where smallpox
was still endemic in 1959 were home to more than
half the world's population. And that total number of annual
cases was probably more like 50 million, not 77,000. This
(14:12):
voluntary program was focused on national vaccine campaigns And at
least in theory, each nation's campaign would be tailored for
its own culture, needs, resources, and infrastructure. But that also
meant there was really no central strategy at work. The
World Health Organization's role was mostly just making sure that
(14:32):
there was enough vaccine available and providing assistance if nations
asked for it. It wasn't really coordinating efforts or doing
a lot of tracking and monitoring. And because under-reporting of
cases continued to be a huge problem, it was almost
impossible to tell whether these national programs were even working.
(14:53):
That made it much harder to secure funding or to
rally support from nations that had already eradicated smallpox within
their own borders. And for the most part, these early
national campaigns were not working, at least not very well.
In many places, success was measured by how many vaccines
were administered. Sometimes this led vaccinators to go after the
(15:14):
easiest targets first, like vaccinating all the students at a school.
But that meant that children in more outlying areas who
were not attending school were not being vaccinated. Since there
often weren't clear records, it wasn't unheard of for vaccinators
to go back to the same school and vaccinate children again,
even though a successful smallpox vaccine typically left a recognizable scar.
(15:39):
Because of issues like this, at one point, India was
reporting a vaccination rate of 140% because so many people
were being vaccinated more than once. Things moved pretty slowly
with all this for about five years. But then in 1964, Dr.
Karel Rashka of Czechoslovakia, who was a huge advocate of
(16:00):
smallpox eradication, became director of the Division of Communicable Diseases
at the World Health Organization. In 1965, the World Health
Organization established a dedicated smallpox eradication unit. And that same year,
President Lyndon Johnson announced that the United States would start
supporting the global smallpox eradication program. Soon, the U.S. was
(16:24):
supporting the work of the Pan American Health Organization in
South America and also funding major vaccine efforts in Western
and Central Africa. These years also saw improvements in how
smallpox vaccines were administered. Most vaccines that people receive today
are administered as shots. They go into the muscle or
(16:44):
the subcutaneous skin layer using a needle. But smallpox vaccine
goes into the skin's superficial layers. By the mid-1960s, there
were a few different methods for doing this. One was
to scratch a person's skin with a needle or lancet,
and another was to repeatedly press the tip of the
needle into a person's skin. Neither of these methods was
(17:05):
very precise. Depending on how skilled the vaccinator was, they
might press the needle too far into the skin or
not far enough. The amount of vaccine on the needle
usually depended on things like how deeply it had been
inserted into the vaccine vial. Excess vaccine was often left
behind on a person's skin and left to either dry
(17:26):
there or be wiped away.
Speaker 1 (17:28):
It was kind of wasteful. It's so fascinating to me
to think about this when I think most of the
vaccines I've received are like those pre-measured, very carefully, like
you open the dose and that's it.
Speaker 2 (17:42):
Yeah.
Speaker 1 (17:43):
So the margin for error of it is a little
bit mind-boggling.
Speaker 2 (17:47):
Yeah. And there are for sure vaccines that are not
administered with shots at this point, but the shots, at
least here in the U.S., are the majority of them.
Speaker 1 (17:56):
The standard, yeah. Yeah. Jet injector devices were made to
try to address some of this and to make vaccinating
more efficient. In theory, these could vaccinate 1,000 people an hour.
But in practice, they were limited. Some required electricity to
work and others were operated with a foot pedal. That
was clunky. So these were only really practical in places
(18:18):
where you could bring huge groups of people to one
location to be vaccinated. Plus, these devices were expensive and
they were hard to clean and they were prone to
breaking down.
Speaker 2 (18:29):
But then Dr. Benjamin A. Rubin developed the bifurcated needle,
which was patented in July of 1965. This was a
simple needle, and when it was inserted into a vaccine vial,
it picked up one measured dose of liquid in between
the two prongs. The prongs themselves were designed to keep
(18:49):
the needle at the correct angle and depth with a
person's skin, and the two-pronged structure meant that it needed
fewer presses into the skin to administer each vaccine.
Speaker 1 (18:59):
This made everything way more efficient.
Speaker 2 (19:02):
One vial of vaccine could be used to vaccinate four
times as many people, and people could be trained to
administer the vaccine with the bifurcated needle in about 15 minutes,
even if they had no previous medical experience.
Speaker 1 (19:17):
Plus, the bifurcated needles were cheap to produce. Although they
were originally intended to be disposable, at the World Health
Organization's request, they were made from a steel alloy that
could hold up Boilable containers were designed so that vaccinators
(19:38):
could drop used needles into the container as they went
and boil the whole thing at the end of a shift.
Speaker 2 (19:44):
Also, it was standard practice to clean a person's arm
with pads that were soaked in alcohol or soap before
giving them the vaccine. I know every time I've gotten
a shot, there's been a little alcohol wipe down on
the injection site. But studies had suggested that this wasn't
actually removing bacteria or other contaminants. It was just sort
(20:07):
of moving things around. Studies confirmed that the number of
complications and secondary infections after smallpox vaccination was the same,
regardless of whether the vaccine site was wiped down beforehand
or not. So most vaccination programs, especially in like more
impoverished areas, dropped this step. And together, all of this
(20:30):
brought the cost for smallpox vaccination down to about 10
cents a person. By 1966, smallpox was endemic in 31 countries.
That was down from the 63 or more reported back
in 1959. The number of estimated worldwide cases had dropped
from about 50 million to somewhere between 10 and 15 million,
(20:52):
although the officially reported tally was still much lower. Somewhere
between 1.5 and 2 million people were still dying of
smallpox per year. This was better. obviously, but it was
also clear that a voluntary vaccination program wasn't going to
be enough to eradicate smallpox. So the World Health Assembly
(21:12):
backed a proposal for an intensified smallpox eradication program, which
would start on January 1st, 1967. Its goal was to
eradicate smallpox worldwide within 10 years, with the last naturally
occurring case being found and isolated by December 31, 1976.
The intensified program was given an initial budget of $ 2. 5 million,
(21:34):
and this was more money than before. But those 31
countries where smallpox was still endemic also had neighbors that
needed to be protected from introduced cases. So this only
worked out to about.
Speaker 1 (21:52):
$ 50, 000 per country. Donald A. Henderson, who was chief of
the Centers for Disease Control's Smallpox Eradication Program, was made
chief medical officer of the Intensified Eradication Program. And in
his account, this 10-year goal was pretty arbitrary. It had
been inspired by John F. Kennedy's declaration that the U.S.
could land a man on the moon within 10 years.
(22:14):
He also described the World Health Organization as pessimistic about
the chances of success. WHO Director General Dr. Marcolina Kandao
was from Brazil and thought smallpox eradication would be impossible
just in the Amazon basin, much less anywhere else. According
to Henderson, the World Health Organization wanted an American to
(22:35):
head the program so that if it failed, the U.S.
would shoulder some of the blame, rather than all of
it falling on the WHO.
Speaker 2 (22:43):
I read a write-up that Henderson wrote briefly about this campaign,
and he had sort of spelled out how it sort
of seemed like things were happening almost immediately. on a whim,
and he was like, I'm writing this to disabuse you
of the notion that there may have been extensive planning
involved in the outset of this. We will get to
(23:07):
how this intensified program, even though it still seemed a
little haphazard, how it successfully eradicated smallpox after another quick
sponsor break. When the World Health Organization established the Intensified
(23:29):
Smallpox Eradication Program, smallpox was still endemic in multiple countries
in Asia, South America, and Sub-Saharan Africa. And especially at first,
a lot of the financial support and a lot of
the vaccines for the program were coming from wealthier nations
where smallpox had already been eradicated, nations like the United States.
(23:50):
And for these countries, their motive was not just humanitarian.
There was also a lot of money and politics involved.
For example, if smallpox was eradicated worldwide, these nations would
not need to fund vaccination programs in other countries or
spend money vaccinating their own populations anymore. For wealthier countries,
(24:13):
these smallpox vaccination programs also served as opportunities to vaccinate
people for other diseases, and to try to build political
influence and goodwill in the places where the programs were operating. Also,
countries where smallpox had been eradicated still occasionally faced outbreaks
that were usually introduced through travel. Although these tended to
(24:35):
be very small and quickly contained, they were still disruptive
and expensive and sometimes sparked a public panic. Global smallpox
eradication would mean not having to deal with any of
that anymore. Yeah, there was a lot of self-interest involved
in the wealthier nations who gave money and vaccine and
other support to this whole program. Although each nation still
(24:59):
needed a plan that was customized to its own needs,
there also needed to be a better unifying strategy behind
this whole program, something beyond a target of vaccinating 80%
of the population.
Speaker 1 (25:13):
That number.
Speaker 2 (25:14):
I feel like it keeps getting repeated today as like
the standard for what is needed, but it had not
really been based on epidemiology or on public health data.
It had just seemed like a reasonable operational goal for
the voluntary program. And it had also become clear that
the number of vaccines administered did not really work as
(25:35):
the goal, since teams might wind up vaccinating the same
people more than once daily. driving up their vaccination numbers
without actually vaccinating more of the population. One big gap
that needed to be filled with this was surveillance. Reporting
methods were still all over the place, and eradication was
only possible if health officials actually knew when and where
(25:58):
outbreaks were happening. This was something that just required a
ton of communication from the World Health Organization and all
through every level of a nation's government's all the way
down to individual doctors, hospitals, and community leaders who needed
to report any suspected cases in order for this to work.
Another gap was standards for the vaccine itself. The Soviet
(26:21):
Union and the United States were the two biggest donors
of vaccines, with the USSR donating 140 million doses a
year and the United States donating 40 million doses. Other
countries donated as well, but in smaller amounts. In 1967,
the World Health Organization asked vaccine manufacturers to submit samples
(26:43):
of their smallpox vaccine, and only 30% of them met
WHO standards for quality and potency. Some of the submitted
vaccine samples did not contain any vaccinia virus at all.
Others were contaminated with bacteria. This led to the WHO
establishing more stringent standards for the vaccines and then monitoring
(27:07):
them to make sure the vaccines actually met those standards.
As all of this was happening, of course, wars and
other unrest were making vaccination programs difficult in some places
where smallpox was still circulating. The Nigerian Civil War began
in 1967, which made things more dangerous for health workers
and their patients, and it also led to a vaccine shortage.
(27:29):
But this shortage also led to a shift in how
smallpox vaccinations were prioritized. Since there wasn't enough vaccine available
for the whole population, health officials focused on vaccinating family
members and other close contacts of anyone who developed smallpox.
This turned out to be an effective way to stop
the spread of the disease, and Nigeria's last smallpox case
(27:51):
was reported in May of 1970. The focus on monitoring
and reporting cases that was so necessary for the program's
success also made it easier to see trends in how
and where smallpox outbreaks developed. Vaccinators started taking better advantage
of seasonal variations. They would use all that surveillance work
(28:13):
to trace people's contacts and to vaccinate more people at
the start of the season when the smallpox case numbers
were lower to contain those outbreaks before they spread. By 1973,
smallpox existed in only five countries. Bangladesh, India, Nepal, Pakistan,
and Ethiopia. Bangladesh had previously been free of the disease,
(28:36):
but it had been reintroduced there as refugees fled the
Indo-Pakistani War. And by this point, about 80% of the
vaccines being used for this effort were being made in
the countries where they were being administered. And at least 95%
of the vaccines that the World Health Organization tested met
its standards. Having only five countries remaining was obviously a
(28:57):
huge accomplishment. But at the same time, more than 700
million people lived in Bangladesh, India, Pakistan, and Nepal. They
were all neighboring countries, and it had become really obvious
that a mass vaccination program just wasn't going to be
able to eradicate the disease in this region. These neighboring
(29:18):
nations had been trying to vaccinate their whole populations for years.
There were 120,000 health staff working on the program in
India alone. So the strategy shifted to mirror what had
actually worked in Nigeria in the late 1960s. Health officials
quarantined anyone who contracted smallpox. and used extensive contact tracing
(29:42):
to determine who else might have been exposed. They vaccinated
their immediate families and the surrounding communities. This became known
as the ring method, basically making a ring of vaccinated
people around each active smallpox case so that the disease
just could not spread. Monitoring and surveillance were critically important
to this process since health workers could only make a
(30:05):
vaccinated ring around cases of smallpox that they knew about.
So health workers traveled from place to place, educating local doctors, healers, leaders,
and officials about smallpox reporting and seeking out and isolating
active smallpox cases and then vaccinating anyone who may have
come into contact with these patients. Using this method, Pakistan
(30:28):
saw its last reported case of smallpox in October of 1974,
Nepal in April of 1975, India in May of 1975,
and Bangladesh in October of 1975. Unfortunately, although Ethiopia's last
case of smallpox was reported in August of 1976, by
(30:49):
that point it had been reintroduced into neighboring Somalia, which
was still experiencing active cases. In 1977, Donald Henderson resigned
as the head of the Intensified Eradication Program. He was
replaced by Asao Arita, who had been medical officer of
infectious disease control in the Ministry of Health and Welfare
(31:09):
in Japan before joining the World Health Organization. That same year, 1977...
authorities started trying to contain an outbreak of variola minor
among nomadic peoples in the desert region that spans parts
of Ethiopia, Somalia, and Kenya. Smallpox was reintroduced into Kenya,
(31:30):
but that introduction was quickly contained, and Kenya reported its
last case in February of 1977. In July of 1977,
Somalia and Ethiopia went to war over control of part
of this region, and then that hampered efforts to control
this ongoing outbreak in Somalia. Somalia actually reported 300 cases
(31:52):
of smallpox in 1977. The last one was the case
of Ali Ma'o Malin, who was a cook at Mirka Hospital.
On October 12, 1977, a driver carrying two smallpox patients
to an isolation camp stopped at the hospital to ask
for directions. Malin got into the car and rode with
them for 15 minutes or less. He did that so
(32:15):
he could guide them to where the leader of the
smallpox surveillance team lived. These two patients were siblings, six
and one and a half years old, and when authorities
traced their contacts, Malin was overlooked. Although Malin worked in
a hospital, he wasn't vaccinated against smallpox. In an interview
later in his life, he said that he had been
afraid of the vaccine. There are a couple of accounts
(32:38):
that said that he had been vaccinated, but his vaccine
hadn't taken, and that disagrees with the interview that he
gave later. He started feeling sick on October 22nd, 1977,
and at first doctors thought he had malaria. Then he
developed a rash on October 26th, and he was initially
diagnosed with chickenpox. He started to worry that he had
(33:00):
smallpox on October 29th, and on October 30th, somebody reported
to health officials that he had a potential smallpox case.
His diagnosis was confirmed through lab tests that day.
Speaker 1 (33:11):
The effort to prevent Malene's smallpox case from sparking another
outbreak really demonstrates what was involved in all of this.
Contact tracing identified 161 possible exposures. some of them as
far as 120 kilometers away. This included hospital staff, family,
and friends, many of whom had visited him while he
(33:33):
was ill. Authorities identified 33 face-to-face contacts who had no
evidence of prior smallpox infection and had not been vaccinated
within the past three years, and 12 of those had
no prior evidence of a smallpox infection or vaccine at all.
Speaker 2 (33:50):
All those people were vaccinated, along with all known and
possible contacts and their families. During an 18-day surveillance period,
health workers made multiple in-person visits to each person who
had potentially been exposed. The number and frequency of those
visits depended on the person's relative level of exposure and
(34:11):
their risk. So if they had been around him a
long time and were not vaccinated, They got multiple different
visits from the health staff, but if they had been
vaccinated and it was a shorter time, they might get
two check-ins. In the end, though, none of those 161
contacts developed smallpox.
Speaker 1 (34:29):
But it did not stop with those 161 contacts. Warning
signs were posted at Merca Hospital, which was placed under
24-hour guard. Vaccines were administered to everyone who worked at
the hospital and all of the patients. Patients in the
surgical ward were quarantined until November 13th, and in the
medical ward, they were quarantined until November 17th. The hospital
(34:52):
also suspended all non-emergency care, referred outpatient procedures to other facilities,
and required daily temperature checks for patients and staff. There
was also a mass vaccination campaign in the ward of
the city where Malene lived and the hospital was. This
was a multi-phase process with vaccinators going house to house
(35:14):
to vaccinate everyone and to look for any signs of
smallpox cases and then returning to vaccinate anybody who had
arrived since the last pass or whose first vaccines showed
no evidence of a vaccine scar. Once that ward of.
Speaker 2 (35:28):
The city was done, health workers did the same for
the rest of the city. Checkpoints were established at all
the roads and footpaths leading into Merca and Anyone who
was coming or going was advised of this possible outbreak.
They vaccinated everybody who was passing through. And then on
top of all of that, there was a massive public
information campaign with a reward for reporting smallpox cases. In
(35:53):
the end, Ali Maomalin was the last person to contract
naturally occurring smallpox. That was 10 years, 9 months, and
26 days after the start of the intensified eradication campaign.
So it just barely missed that 10-year goal, even if
it had been arbitrary. After recovering from smallpox, Malin later
(36:13):
became part of the effort to eradicate polio, working as
a vaccinator and organizing door-to-door campaigns. He would share his
own story about how he had been afraid to be
vaccinated for smallpox and then had ultimately become the last
smallpox patient. Somalia was declared free of polio in 2007,
but it re-emerged there in 2013. When that happened, Malin
(36:37):
went back to his vaccinating work. He suddenly became ill
not long afterward, and he died on July 22, 2013,
of what was diagnosed as malaria.
Speaker 1 (36:48):
But the last person to die of smallpox contracted it
after Malin did. That was Janet Parker, a medical photographer
who was infected on the job at England's Birmingham University
Medical School in 1978. The microbiology lab was one floor
below her darkroom in the office that she used to
make phone calls. It is not clear exactly how she
(37:11):
came into contact with smallpox virus from the lab. At
the time, the prevailing theory was that it was through
a shared air vent, but later studies suggested that that
was actually unlikely. Parker had been vaccinated for smallpox, but
as we mentioned earlier, the vaccine's protection was expected to
last for about 10 years, and she had been vaccinated
(37:32):
back in 1966. The strain she was exposed to was
also a particularly deadly one. Her mother, Hilda Whitcomb, contracted
smallpox while caring for her, but she recovered. But Janet's father, Frederick,
died of an apparent heart attack while in quarantine. Hilda
missed both his and Janet's funerals because of her own illness.
(37:55):
Health workers quarantined hundreds of people who had possibly been exposed,
and at least 500 people were vaccinated to keep this
outbreak from spreading any further. This lab had been scheduled
to close as the World Health Organization tried to reduce
the number of facilities that had samples of the virus.
Although the lab had previously been inspected and was allowed
(38:18):
to continue operation... it didn't have a lot of basic
safety measures in place to contain deadly pathogens. Things like
changing facilities, dedicated showers, and airlocks. It also had been
the source of another smallpox case, also involving a medical photographer,
back in 1966.
Speaker 2 (38:35):
It really seems like when they inspected the lab and
they were like, it doesn't have all these things that
we recommend to control potential spread of pathogens, but like
only three people work here, so it's probably fine. This
became a huge scandal later. The lab's director, Dr. Henry Bedsen,
had been trying to finish as much of his work
(38:56):
as possible before the lab was closed. He blamed himself
for Parker's illness and took his own life a few
days before her death, which was on September 11, 1978.
As this was happening, health officials were still closely monitoring
other countries to confirm that smallpox was no longer circulating there.
(39:16):
On October 26, 1979, A ceremony was held in Nairobi
to announce that smallpox had been eradicated in the Horn
of Africa. That was two years after Ali Ma'aumaline had
first developed a smallpox rash. On December 9, 1979, the
Global Commission for the Certification of Smallpox Eradication declared smallpox eradicated.
(39:38):
And on May 8, 1980, the World Health Organization confirmed
the disease's eradication. There's been some stuff floating around social
media lately about how this was only possible because everyone
did their part, either implying or just flat out saying
that everybody accepted the vaccine during this process. But that
(39:59):
is just not true. There was a lot of resistance
and hesitancy, especially in campaigns to vaccinate children. A lot
of parents just didn't want to do something that might
hurt their child or make them sick. The process of
Administering the vaccine also evolved over the years, and some
parents had had, like, pretty traumatic vaccine experiences that they
(40:20):
didn't want repeated with their child. Anti-vaccine activists such as
Lily Lote, who worked for the National Anti-Vaccination League and
edited its journal, distributed literature against vaccines in general and
against the smallpox vaccine specifically well into this eradication effort.
Aside from that, because earlier versions of the smallpox vaccine
(40:43):
were grown in the skin of live animals, animal rights
activists and anti-vivisectionists objected to their use. When methods progressed
to using tissue cultures, mistrust of science led people to
object to this method as well. In places like India,
smallpox vaccination had been a routine part of the public
health service since 1947, and yet there were still outbreaks
(41:07):
for decades after that. This led people to claim that
the vaccine was worthless, or even that it was what
had been causing the smallpox. Nations stopped vaccinating people for
smallpox once the disease had been eradicated from within their borders,
and in some people, this just reinforced that perception. Like,
there were no vaccines happening anymore. That must be why
(41:29):
there's no smallpox happening anymore. There were also religious objections
to smallpox vaccinations. Various peoples and cultures interpreted smallpox as
coming from divine will, or interpreted existing methods of smallpox
prevention or treatment as religiously significant. And most of the
last nations to eradicate smallpox were the same ones that
(41:51):
had a long history of being colonized and exploited by
European powers. So people were understandably suspicious of this largely
Western-led public health effort. So the global eradication of smallpox
happened in spite of hesitancy and resistance, not in the
absence of it. So that is how smallpox was finally eradicated.
(42:15):
It does still exist in a couple of labs. There
have been ongoing conversations about destroying those remaining stocks, and
it keeps getting postponed. I would really like it if
we as a global society could get control of the
COVID-19 pandemic, because unless.
Speaker 1 (42:33):
The Carter Center program.
Speaker 2 (42:35):
successfully eradicates guinea worm disease in the immediate future. We
don't have any more eradications of diseases to cover on
this show when I need an optimistic story related to
all this.
Speaker 1 (42:49):
Right. That would be great to report as a history
in the making, but fingers crossed.
Speaker 2 (43:03):
Thanks so much for joining us on this Saturday. If
you'd like to send us a note, our email address
is historypodcast at iheartradio.com. And you can subscribe to the
show on the iHeartRadio app, Apple Podcasts, or wherever you
listen to your favorite shows.
Happy Saturday.
Speaker 2 (00:03):
Since we mentioned our episode on the eradication of smallpox
this week, we are bringing it out as today's Saturday classic.
At the end of this episode, we mentioned guinea worm disease,
also called draconchioliasis, as a disease that could potentially be eradicated.
According to the World Health Organization, in 2025, there were
(00:23):
10 reported cases of draconchioliasis. There were 15 in 2024,
14 in 2023, and.
Speaker 1 (00:33):
13 in 2022.
Speaker 2 (00:34):
This episode originally came out September 1st, 2021. Enjoy!
Speaker 1 (00:41):
Welcome to Stuff You Missed in History Class, a production
of iHeartRadio.
Speaker 2 (00:51):
Hello and welcome to the podcast. I'm Tracy V.
Speaker 1 (00:54):
Wilson. And I'm Holly Frey.
Speaker 2 (00:57):
Late March of last year, I researched and wrote our
episode on the eradication of render pests. Because in that moment,
it just felt really weird to me to work on
episodes that were not about the pandemic somehow. Because that
was dominating everything in our lives. But at the same time,
I wanted to work on something that felt kind of optimistic.
(01:20):
Because the pandemic was dominating our lives. So now it's
almost a year and a half later. Here in the U.S.,
we had a pretty hopeful springtime regarding the progress of
the pandemic. I know that was not the case in
the whole world, but we had what was looking like
improved situations. That obviously has taken a turn once again
(01:45):
for the worst, or at least the worst, maybe not
the worst of ever, but definitely worse. I wanted to
kind of return to the idea of wiping a disease
off the face of the earth. So, rinderpest and smallpox
are the only two diseases that have been eradicated through
human activity. Neither one of them is technically extinct because
(02:07):
there are some samples of both viruses that still exist
in labs. They're no longer circulating out in the wild, though.
And we've talked about smallpox a bit on the show before.
We had our episode on Edward Jenner and the smallpox
vaccine and how the vaccine was developed and then Jenner's
efforts to try.
Speaker 1 (02:24):
To make it more widely available.
Speaker 2 (02:27):
More recently, we did the episode on the Royal Philanthropic
Vaccine Expedition, and that was all about Spain's efforts to
transport the smallpox vaccine to the Americas, which required a
chain of living human hosts.
Speaker 1 (02:41):
We mentioned.
Speaker 2 (02:42):
pretty briefly, the eradication of smallpox in both of those episodes,
but we have not gone into detail about how that happened.
That's what we're going to talk about today. And when
Tracy mentioned it to me, I said, we've covered that.
Speaker 1 (02:58):
Nope. It just keeps coming up. It just keeps coming up.
Speaker 2 (03:01):
We've said in like a sentence how it was done,
but it's more than a sentence worth of explanation. Yeah. Yeah.
Speaker 1 (03:08):
It's just, it's been... just peppered in enough that my
brain was like, yeah, that was an episode, right? Nope. Nope.
So smallpox is a viral disease that has existed for millennia.
When it was circulating in the wild, it spread from
person to person through the air, usually through face-to-face contact,
and it can also be spread through contact with contaminated
(03:30):
objects and surfaces. People who contracted smallpox typically developed a
high fever and body aches, and that was followed by
a distinctive rash. There are two different strains of the
variola virus that were causing smallpox, variola major and variola minor.
As that name suggests, variola major caused more serious illnesses.
(03:52):
As many as a third of people who were infected
with variola major died. As many as 90% of babies died.
Speaker 2 (04:00):
It was also particularly lethal anytime it was introduced somewhere
that it hadn't existed before, such as when Europeans started
arriving in the Americas. And in those cases, smallpox usually
killed about half the people who contracted it. Among the
people who survived the disease, smallpox could also be both
disabling and disfiguring.
Speaker 1 (04:21):
There was and is no cure for smallpox. So even
as science and medicine progressed, it continued to be deadly.
but it also had some traits that made it a
good candidate for a worldwide eradication campaign. Smallpox was easy
to recognize and diagnose, unlike, say, the flu, which can
resemble a lot of other respiratory infections. Smallpox passed directly
(04:45):
from person to person and only infected humans, so there
were no hidden reservoirs of the virus that could potentially
start a new outbreak. That's different from something like yellow fever,
which also infects other primates, and is transmitted by mosquitoes.
Another plus, once a person had recovered from smallpox, they
were immune for life. For a number of reasons, smallpox
(05:10):
outbreaks also tended to develop relatively slowly. Once people were contagious,
they were usually also too sick to really leave home,
so outbreaks tended to cluster around members of the same
household and their immediate neighborhood. And then once an outbreak
was identified, swift action could keep it from spreading very far.
(05:30):
And most importantly, there was a way to disrupt transmission
of the disease, in this case, a vaccine. In terms
of the smallpox vaccine, at first, people prevented smallpox using
a technique called variolation that involved intentionally introducing material from
one person's smallpox sore or scab into another person. Practitioners
(05:52):
in Asia were doing this as early as the 11th century,
and the technique spread from there. Then, in the late
18th century, people started to make a connection between smallpox
and another much milder disease that was called cowpox. The
smallpox and cowpox viruses are both in the genus Orthopoxvirus,
and people who had contracted cowpox seemed immune to smallpox.
(06:16):
Several people, including Edward Jenner, tried deliberately exposing people to cowpox,
as a way to prevent smallpox. Jenner called this vaccination
after the Latin word for cow.
Speaker 2 (06:28):
So both variolation and vaccination could prevent smallpox, but since
variolation could also cause full-blown smallpox, vaccination was a lot safer.
At the same time, though, vaccination in its earliest forms
carried some of the same risks that variolation did, including
the potential for transmitting other illnesses like syphilis and hepatitis
(06:51):
from person to person during these person-to-person vaccination chains. Sometime
in the 19th century, people shifted from using cowpox to
using vaccinia virus, which is another orthopox virus, to make
smallpox vaccine. The origins of the vaccinia virus are unclear.
It is possible that it's actually some kind of hybrid
(07:12):
of cowpox and and smallpox, or that it developed over
time as cowpox virus was passed through multiple hosts in
the process of making vaccines. Eventually, vaccinia virus replaced cowpox
virus for vaccination purposes, just as vaccination with cowpox had
previously replaced variolation with smallpox itself. At first, vaccines made
(07:36):
with vaccinia virus were grown in the skin of live
animals like calves, sheep, and rabbits. Eventually, that shifted to
growing the virus in tissue cultures or in chicken eggs.
These methods replaced those arm-to-arm vaccination chains that we talked
about in our episode on the Royal Philanthropic Vaccine Expedition.
(07:57):
Countries actually started to outlaw arm-to-arm vaccinations in the late
19th century. Many of the vaccinia strains used to make
vaccines were attenuated or weakened by repeatedly passing them through
a non-human host. things like chick embryo cells, eggs, or mice.
This process resulted in a virus that produced an immune
(08:18):
response when a person was vaccinated with it, but couldn't
reproduce in that person's body and make them sick. So
while vaccination with cowpox virus was safer than variolation with
smallpox virus, vaccination with an attenuated version of vaccinia virus
was also safer than vaccination with live, unattenuated cowpox. Yeah,
(08:39):
there were still potentials for various complications, but this was
an improvement overall. It really didn't take long after the
development of vaccines for people to wonder whether vaccines could
be used to eliminate smallpox entirely. But early attempts to
do this faced a lot of obstacles. As we talked
(08:59):
about in our episode on the Royal Philanthropic Vaccine Expedition,
early versions of smallpox vaccine lost their potency really quickly,
especially in hot weather. And that continued to be true
after vaccinia replaced cowpox as the preferred virus for smallpox vaccines.
But then in the 1940s, people started working on dehydrated
(09:21):
and freeze-dried versions of the vaccine. The Vaccine Institute in
Paris produced a freeze-dried, vacuum-packed vaccine that had a longer
shelf life. In the 1950s, Leslie Harold Collier at the
Lister Institute studied the preservation methods that were in use
and how effective they were, and he developed a process
that didn't require refrigeration, even in tropical temperatures. Once the
(09:45):
vaccine was reconstituted, it still had a short shelf life,
but until that point, it could survive in the field
for months. It also protected people from smallpox infection for
at least 10 years and offered protection against dying of
smallpox for some time after that. Collier's method eventually became
the World Health Organization standard for vaccine used for the
(10:07):
eradication campaign. Smallpox was eliminated in North America in 1952
and in Europe in 1953. And that was done primarily
through mass vaccination campaigns, especially ones that were done in
response to outbreaks. And this success came in spite of
increasing resistance to vaccines and to compulsory vaccine programs. In
(10:30):
the United States, this resistance led to a Supreme Court
case in 1905, The city of Cambridge, Massachusetts, had been
trying to stop a smallpox outbreak and had ordered all
adults to be vaccinated or to pay a $ 5 fine.
Henning Jacobson refused to be vaccinated, and then after being fined,
he took the matter to court. In the words of
(10:52):
the court's decision, quote, the liberty secured by the Constitution
of the United States does not import an absolute right
in each person to be at all times and in
all circumstances wholly freed from restraint. nor is it an
element in such liberty that one person or a minority
of persons residing in any community and enjoying the benefits
(11:13):
of local government should have power to dominate the majority
when supported in their action by the authority of the state.
It is within the police power of a state to
enact a compulsory vaccination law, and it is for the
legislature and not for the courts to determine in the
first instance whether vaccination is or is not the best
mode for the prevention of smallpox, and the protection of
(11:36):
the public health. We'll get some more on the campaign
to eradicate smallpox in the rest of the world after
a sponsor break. The World Health Organization's decision-making body is
(11:56):
called the World Health Assembly. And in 1953, the WHA
didn't consider smallpox to be a candidate for global eradication.
It just wasn't a priority. But five years later, a
delegate to the WHA proposed a 10-year eradication plan. That
delegate was Professor Viktor Zhdanov, who was deputy health minister
(12:18):
of the Soviet Union. And this proposal included vaccine donations
that would be provided by the USSR. But even with
the promise of donated vaccines, this proposal still didn't pass.
At the time, the World Health Organization was working on
an anti-malaria program, and that was really just drawing most
of the focus. In 1959, the Soviet Union's proposal was reintroduced,
(12:42):
and this time it was passed as a voluntary global
vaccine campaign. Countries where smallpox was endemic, that is, freely circulating,
were asked to institute mass vaccine programs with a goal
of vaccinating 80% of their populations. And the countries where
it wasn't, which were generally richer, were asked to contribute
(13:02):
funding or vaccines toward the effort. At that point, smallpox
was being reported in 63 countries, and together those countries
reported 77,555 cases of the disease. but it became obvious
really fast that that number was way, way too low.
For one thing, those 63 countries only included the ones
(13:26):
that were members of the World Health Organization, and some
countries where smallpox was endemic were not members at that point,
and that included China, which had a population of more
than 660 million people. But even in those 63 countries,
reporting was all over the place. In countries without a
lot of public health infrastructure, smallpox cases weren't really being tracked.
(13:48):
But even in places where that wasn't the case, sometimes
the only smallpox infections being reported were the ones that
ended up in hospitals. In reality, the countries where smallpox
was still endemic in 1959 were home to more than
half the world's population. And that total number of annual
cases was probably more like 50 million, not 77,000. This
(14:12):
voluntary program was focused on national vaccine campaigns And at
least in theory, each nation's campaign would be tailored for
its own culture, needs, resources, and infrastructure. But that also
meant there was really no central strategy at work. The
World Health Organization's role was mostly just making sure that
(14:32):
there was enough vaccine available and providing assistance if nations
asked for it. It wasn't really coordinating efforts or doing
a lot of tracking and monitoring. And because under-reporting of
cases continued to be a huge problem, it was almost
impossible to tell whether these national programs were even working.
(14:53):
That made it much harder to secure funding or to
rally support from nations that had already eradicated smallpox within
their own borders. And for the most part, these early
national campaigns were not working, at least not very well.
In many places, success was measured by how many vaccines
were administered. Sometimes this led vaccinators to go after the
(15:14):
easiest targets first, like vaccinating all the students at a school.
But that meant that children in more outlying areas who
were not attending school were not being vaccinated. Since there
often weren't clear records, it wasn't unheard of for vaccinators
to go back to the same school and vaccinate children again,
even though a successful smallpox vaccine typically left a recognizable scar.
(15:39):
Because of issues like this, at one point, India was
reporting a vaccination rate of 140% because so many people
were being vaccinated more than once. Things moved pretty slowly
with all this for about five years. But then in 1964, Dr.
Karel Rashka of Czechoslovakia, who was a huge advocate of
(16:00):
smallpox eradication, became director of the Division of Communicable Diseases
at the World Health Organization. In 1965, the World Health
Organization established a dedicated smallpox eradication unit. And that same year,
President Lyndon Johnson announced that the United States would start
supporting the global smallpox eradication program. Soon, the U.S. was
(16:24):
supporting the work of the Pan American Health Organization in
South America and also funding major vaccine efforts in Western
and Central Africa. These years also saw improvements in how
smallpox vaccines were administered. Most vaccines that people receive today
are administered as shots. They go into the muscle or
(16:44):
the subcutaneous skin layer using a needle. But smallpox vaccine
goes into the skin's superficial layers. By the mid-1960s, there
were a few different methods for doing this. One was
to scratch a person's skin with a needle or lancet,
and another was to repeatedly press the tip of the
needle into a person's skin. Neither of these methods was
(17:05):
very precise. Depending on how skilled the vaccinator was, they
might press the needle too far into the skin or
not far enough. The amount of vaccine on the needle
usually depended on things like how deeply it had been
inserted into the vaccine vial. Excess vaccine was often left
behind on a person's skin and left to either dry
(17:26):
there or be wiped away.
Speaker 1 (17:28):
It was kind of wasteful. It's so fascinating to me
to think about this when I think most of the
vaccines I've received are like those pre-measured, very carefully, like
you open the dose and that's it.
Speaker 2 (17:42):
Yeah.
Speaker 1 (17:43):
So the margin for error of it is a little
bit mind-boggling.
Speaker 2 (17:47):
Yeah. And there are for sure vaccines that are not
administered with shots at this point, but the shots, at
least here in the U.S., are the majority of them.
Speaker 1 (17:56):
The standard, yeah. Yeah. Jet injector devices were made to
try to address some of this and to make vaccinating
more efficient. In theory, these could vaccinate 1,000 people an hour.
But in practice, they were limited. Some required electricity to
work and others were operated with a foot pedal. That
was clunky. So these were only really practical in places
(18:18):
where you could bring huge groups of people to one
location to be vaccinated. Plus, these devices were expensive and
they were hard to clean and they were prone to
breaking down.
Speaker 2 (18:29):
But then Dr. Benjamin A. Rubin developed the bifurcated needle,
which was patented in July of 1965. This was a
simple needle, and when it was inserted into a vaccine vial,
it picked up one measured dose of liquid in between
the two prongs. The prongs themselves were designed to keep
(18:49):
the needle at the correct angle and depth with a
person's skin, and the two-pronged structure meant that it needed
fewer presses into the skin to administer each vaccine.
Speaker 1 (18:59):
This made everything way more efficient.
Speaker 2 (19:02):
One vial of vaccine could be used to vaccinate four
times as many people, and people could be trained to
administer the vaccine with the bifurcated needle in about 15 minutes,
even if they had no previous medical experience.
Speaker 1 (19:17):
Plus, the bifurcated needles were cheap to produce. Although they
were originally intended to be disposable, at the World Health
Organization's request, they were made from a steel alloy that
could hold up Boilable containers were designed so that vaccinators
(19:38):
could drop used needles into the container as they went
and boil the whole thing at the end of a shift.
Speaker 2 (19:44):
Also, it was standard practice to clean a person's arm
with pads that were soaked in alcohol or soap before
giving them the vaccine. I know every time I've gotten
a shot, there's been a little alcohol wipe down on
the injection site. But studies had suggested that this wasn't
actually removing bacteria or other contaminants. It was just sort
(20:07):
of moving things around. Studies confirmed that the number of
complications and secondary infections after smallpox vaccination was the same,
regardless of whether the vaccine site was wiped down beforehand
or not. So most vaccination programs, especially in like more
impoverished areas, dropped this step. And together, all of this
(20:30):
brought the cost for smallpox vaccination down to about 10
cents a person. By 1966, smallpox was endemic in 31 countries.
That was down from the 63 or more reported back
in 1959. The number of estimated worldwide cases had dropped
from about 50 million to somewhere between 10 and 15 million,
(20:52):
although the officially reported tally was still much lower. Somewhere
between 1.5 and 2 million people were still dying of
smallpox per year. This was better. obviously, but it was
also clear that a voluntary vaccination program wasn't going to
be enough to eradicate smallpox. So the World Health Assembly
(21:12):
backed a proposal for an intensified smallpox eradication program, which
would start on January 1st, 1967. Its goal was to
eradicate smallpox worldwide within 10 years, with the last naturally
occurring case being found and isolated by December 31, 1976.
The intensified program was given an initial budget of $ 2. 5 million,
(21:34):
and this was more money than before. But those 31
countries where smallpox was still endemic also had neighbors that
needed to be protected from introduced cases. So this only
worked out to about.
Speaker 1 (21:52):
$ 50, 000 per country. Donald A. Henderson, who was chief of
the Centers for Disease Control's Smallpox Eradication Program, was made
chief medical officer of the Intensified Eradication Program. And in
his account, this 10-year goal was pretty arbitrary. It had
been inspired by John F. Kennedy's declaration that the U.S.
could land a man on the moon within 10 years.
(22:14):
He also described the World Health Organization as pessimistic about
the chances of success. WHO Director General Dr. Marcolina Kandao
was from Brazil and thought smallpox eradication would be impossible
just in the Amazon basin, much less anywhere else. According
to Henderson, the World Health Organization wanted an American to
(22:35):
head the program so that if it failed, the U.S.
would shoulder some of the blame, rather than all of
it falling on the WHO.
Speaker 2 (22:43):
I read a write-up that Henderson wrote briefly about this campaign,
and he had sort of spelled out how it sort
of seemed like things were happening almost immediately. on a whim,
and he was like, I'm writing this to disabuse you
of the notion that there may have been extensive planning
involved in the outset of this. We will get to
(23:07):
how this intensified program, even though it still seemed a
little haphazard, how it successfully eradicated smallpox after another quick
sponsor break. When the World Health Organization established the Intensified
(23:29):
Smallpox Eradication Program, smallpox was still endemic in multiple countries
in Asia, South America, and Sub-Saharan Africa. And especially at first,
a lot of the financial support and a lot of
the vaccines for the program were coming from wealthier nations
where smallpox had already been eradicated, nations like the United States.
(23:50):
And for these countries, their motive was not just humanitarian.
There was also a lot of money and politics involved.
For example, if smallpox was eradicated worldwide, these nations would
not need to fund vaccination programs in other countries or
spend money vaccinating their own populations anymore. For wealthier countries,
(24:13):
these smallpox vaccination programs also served as opportunities to vaccinate
people for other diseases, and to try to build political
influence and goodwill in the places where the programs were operating. Also,
countries where smallpox had been eradicated still occasionally faced outbreaks
that were usually introduced through travel. Although these tended to
(24:35):
be very small and quickly contained, they were still disruptive
and expensive and sometimes sparked a public panic. Global smallpox
eradication would mean not having to deal with any of
that anymore. Yeah, there was a lot of self-interest involved
in the wealthier nations who gave money and vaccine and
other support to this whole program. Although each nation still
(24:59):
needed a plan that was customized to its own needs,
there also needed to be a better unifying strategy behind
this whole program, something beyond a target of vaccinating 80%
of the population.
Speaker 1 (25:13):
That number.
Speaker 2 (25:14):
I feel like it keeps getting repeated today as like
the standard for what is needed, but it had not
really been based on epidemiology or on public health data.
It had just seemed like a reasonable operational goal for
the voluntary program. And it had also become clear that
the number of vaccines administered did not really work as
(25:35):
the goal, since teams might wind up vaccinating the same
people more than once daily. driving up their vaccination numbers
without actually vaccinating more of the population. One big gap
that needed to be filled with this was surveillance. Reporting
methods were still all over the place, and eradication was
only possible if health officials actually knew when and where
(25:58):
outbreaks were happening. This was something that just required a
ton of communication from the World Health Organization and all
through every level of a nation's government's all the way
down to individual doctors, hospitals, and community leaders who needed
to report any suspected cases in order for this to work.
Another gap was standards for the vaccine itself. The Soviet
(26:21):
Union and the United States were the two biggest donors
of vaccines, with the USSR donating 140 million doses a
year and the United States donating 40 million doses. Other
countries donated as well, but in smaller amounts. In 1967,
the World Health Organization asked vaccine manufacturers to submit samples
(26:43):
of their smallpox vaccine, and only 30% of them met
WHO standards for quality and potency. Some of the submitted
vaccine samples did not contain any vaccinia virus at all.
Others were contaminated with bacteria. This led to the WHO
establishing more stringent standards for the vaccines and then monitoring
(27:07):
them to make sure the vaccines actually met those standards.
As all of this was happening, of course, wars and
other unrest were making vaccination programs difficult in some places
where smallpox was still circulating. The Nigerian Civil War began
in 1967, which made things more dangerous for health workers
and their patients, and it also led to a vaccine shortage.
(27:29):
But this shortage also led to a shift in how
smallpox vaccinations were prioritized. Since there wasn't enough vaccine available
for the whole population, health officials focused on vaccinating family
members and other close contacts of anyone who developed smallpox.
This turned out to be an effective way to stop
the spread of the disease, and Nigeria's last smallpox case
(27:51):
was reported in May of 1970. The focus on monitoring
and reporting cases that was so necessary for the program's
success also made it easier to see trends in how
and where smallpox outbreaks developed. Vaccinators started taking better advantage
of seasonal variations. They would use all that surveillance work
(28:13):
to trace people's contacts and to vaccinate more people at
the start of the season when the smallpox case numbers
were lower to contain those outbreaks before they spread. By 1973,
smallpox existed in only five countries. Bangladesh, India, Nepal, Pakistan,
and Ethiopia. Bangladesh had previously been free of the disease,
(28:36):
but it had been reintroduced there as refugees fled the
Indo-Pakistani War. And by this point, about 80% of the
vaccines being used for this effort were being made in
the countries where they were being administered. And at least 95%
of the vaccines that the World Health Organization tested met
its standards. Having only five countries remaining was obviously a
(28:57):
huge accomplishment. But at the same time, more than 700
million people lived in Bangladesh, India, Pakistan, and Nepal. They
were all neighboring countries, and it had become really obvious
that a mass vaccination program just wasn't going to be
able to eradicate the disease in this region. These neighboring
(29:18):
nations had been trying to vaccinate their whole populations for years.
There were 120,000 health staff working on the program in
India alone. So the strategy shifted to mirror what had
actually worked in Nigeria in the late 1960s. Health officials
quarantined anyone who contracted smallpox. and used extensive contact tracing
(29:42):
to determine who else might have been exposed. They vaccinated
their immediate families and the surrounding communities. This became known
as the ring method, basically making a ring of vaccinated
people around each active smallpox case so that the disease
just could not spread. Monitoring and surveillance were critically important
to this process since health workers could only make a
(30:05):
vaccinated ring around cases of smallpox that they knew about.
So health workers traveled from place to place, educating local doctors, healers, leaders,
and officials about smallpox reporting and seeking out and isolating
active smallpox cases and then vaccinating anyone who may have
come into contact with these patients. Using this method, Pakistan
(30:28):
saw its last reported case of smallpox in October of 1974,
Nepal in April of 1975, India in May of 1975,
and Bangladesh in October of 1975. Unfortunately, although Ethiopia's last
case of smallpox was reported in August of 1976, by
(30:49):
that point it had been reintroduced into neighboring Somalia, which
was still experiencing active cases. In 1977, Donald Henderson resigned
as the head of the Intensified Eradication Program. He was
replaced by Asao Arita, who had been medical officer of
infectious disease control in the Ministry of Health and Welfare
(31:09):
in Japan before joining the World Health Organization. That same year, 1977...
authorities started trying to contain an outbreak of variola minor
among nomadic peoples in the desert region that spans parts
of Ethiopia, Somalia, and Kenya. Smallpox was reintroduced into Kenya,
(31:30):
but that introduction was quickly contained, and Kenya reported its
last case in February of 1977. In July of 1977,
Somalia and Ethiopia went to war over control of part
of this region, and then that hampered efforts to control
this ongoing outbreak in Somalia. Somalia actually reported 300 cases
(31:52):
of smallpox in 1977. The last one was the case
of Ali Ma'o Malin, who was a cook at Mirka Hospital.
On October 12, 1977, a driver carrying two smallpox patients
to an isolation camp stopped at the hospital to ask
for directions. Malin got into the car and rode with
them for 15 minutes or less. He did that so
(32:15):
he could guide them to where the leader of the
smallpox surveillance team lived. These two patients were siblings, six
and one and a half years old, and when authorities
traced their contacts, Malin was overlooked. Although Malin worked in
a hospital, he wasn't vaccinated against smallpox. In an interview
later in his life, he said that he had been
afraid of the vaccine. There are a couple of accounts
(32:38):
that said that he had been vaccinated, but his vaccine
hadn't taken, and that disagrees with the interview that he
gave later. He started feeling sick on October 22nd, 1977,
and at first doctors thought he had malaria. Then he
developed a rash on October 26th, and he was initially
diagnosed with chickenpox. He started to worry that he had
(33:00):
smallpox on October 29th, and on October 30th, somebody reported
to health officials that he had a potential smallpox case.
His diagnosis was confirmed through lab tests that day.
Speaker 1 (33:11):
The effort to prevent Malene's smallpox case from sparking another
outbreak really demonstrates what was involved in all of this.
Contact tracing identified 161 possible exposures. some of them as
far as 120 kilometers away. This included hospital staff, family,
and friends, many of whom had visited him while he
(33:33):
was ill. Authorities identified 33 face-to-face contacts who had no
evidence of prior smallpox infection and had not been vaccinated
within the past three years, and 12 of those had
no prior evidence of a smallpox infection or vaccine at all.
Speaker 2 (33:50):
All those people were vaccinated, along with all known and
possible contacts and their families. During an 18-day surveillance period,
health workers made multiple in-person visits to each person who
had potentially been exposed. The number and frequency of those
visits depended on the person's relative level of exposure and
(34:11):
their risk. So if they had been around him a
long time and were not vaccinated, They got multiple different
visits from the health staff, but if they had been
vaccinated and it was a shorter time, they might get
two check-ins. In the end, though, none of those 161
contacts developed smallpox.
Speaker 1 (34:29):
But it did not stop with those 161 contacts. Warning
signs were posted at Merca Hospital, which was placed under
24-hour guard. Vaccines were administered to everyone who worked at
the hospital and all of the patients. Patients in the
surgical ward were quarantined until November 13th, and in the
medical ward, they were quarantined until November 17th. The hospital
(34:52):
also suspended all non-emergency care, referred outpatient procedures to other facilities,
and required daily temperature checks for patients and staff. There
was also a mass vaccination campaign in the ward of
the city where Malene lived and the hospital was. This
was a multi-phase process with vaccinators going house to house
(35:14):
to vaccinate everyone and to look for any signs of
smallpox cases and then returning to vaccinate anybody who had
arrived since the last pass or whose first vaccines showed
no evidence of a vaccine scar. Once that ward of.
Speaker 2 (35:28):
The city was done, health workers did the same for
the rest of the city. Checkpoints were established at all
the roads and footpaths leading into Merca and Anyone who
was coming or going was advised of this possible outbreak.
They vaccinated everybody who was passing through. And then on
top of all of that, there was a massive public
information campaign with a reward for reporting smallpox cases. In
(35:53):
the end, Ali Maomalin was the last person to contract
naturally occurring smallpox. That was 10 years, 9 months, and
26 days after the start of the intensified eradication campaign.
So it just barely missed that 10-year goal, even if
it had been arbitrary. After recovering from smallpox, Malin later
(36:13):
became part of the effort to eradicate polio, working as
a vaccinator and organizing door-to-door campaigns. He would share his
own story about how he had been afraid to be
vaccinated for smallpox and then had ultimately become the last
smallpox patient. Somalia was declared free of polio in 2007,
but it re-emerged there in 2013. When that happened, Malin
(36:37):
went back to his vaccinating work. He suddenly became ill
not long afterward, and he died on July 22, 2013,
of what was diagnosed as malaria.
Speaker 1 (36:48):
But the last person to die of smallpox contracted it
after Malin did. That was Janet Parker, a medical photographer
who was infected on the job at England's Birmingham University
Medical School in 1978. The microbiology lab was one floor
below her darkroom in the office that she used to
make phone calls. It is not clear exactly how she
(37:11):
came into contact with smallpox virus from the lab. At
the time, the prevailing theory was that it was through
a shared air vent, but later studies suggested that that
was actually unlikely. Parker had been vaccinated for smallpox, but
as we mentioned earlier, the vaccine's protection was expected to
last for about 10 years, and she had been vaccinated
(37:32):
back in 1966. The strain she was exposed to was
also a particularly deadly one. Her mother, Hilda Whitcomb, contracted
smallpox while caring for her, but she recovered. But Janet's father, Frederick,
died of an apparent heart attack while in quarantine. Hilda
missed both his and Janet's funerals because of her own illness.
(37:55):
Health workers quarantined hundreds of people who had possibly been exposed,
and at least 500 people were vaccinated to keep this
outbreak from spreading any further. This lab had been scheduled
to close as the World Health Organization tried to reduce
the number of facilities that had samples of the virus.
Although the lab had previously been inspected and was allowed
(38:18):
to continue operation... it didn't have a lot of basic
safety measures in place to contain deadly pathogens. Things like
changing facilities, dedicated showers, and airlocks. It also had been
the source of another smallpox case, also involving a medical photographer,
back in 1966.
Speaker 2 (38:35):
It really seems like when they inspected the lab and
they were like, it doesn't have all these things that
we recommend to control potential spread of pathogens, but like
only three people work here, so it's probably fine. This
became a huge scandal later. The lab's director, Dr. Henry Bedsen,
had been trying to finish as much of his work
(38:56):
as possible before the lab was closed. He blamed himself
for Parker's illness and took his own life a few
days before her death, which was on September 11, 1978.
As this was happening, health officials were still closely monitoring
other countries to confirm that smallpox was no longer circulating there.
(39:16):
On October 26, 1979, A ceremony was held in Nairobi
to announce that smallpox had been eradicated in the Horn
of Africa. That was two years after Ali Ma'aumaline had
first developed a smallpox rash. On December 9, 1979, the
Global Commission for the Certification of Smallpox Eradication declared smallpox eradicated.
(39:38):
And on May 8, 1980, the World Health Organization confirmed
the disease's eradication. There's been some stuff floating around social
media lately about how this was only possible because everyone
did their part, either implying or just flat out saying
that everybody accepted the vaccine during this process. But that
(39:59):
is just not true. There was a lot of resistance
and hesitancy, especially in campaigns to vaccinate children. A lot
of parents just didn't want to do something that might
hurt their child or make them sick. The process of
Administering the vaccine also evolved over the years, and some
parents had had, like, pretty traumatic vaccine experiences that they
(40:20):
didn't want repeated with their child. Anti-vaccine activists such as
Lily Lote, who worked for the National Anti-Vaccination League and
edited its journal, distributed literature against vaccines in general and
against the smallpox vaccine specifically well into this eradication effort.
Aside from that, because earlier versions of the smallpox vaccine
(40:43):
were grown in the skin of live animals, animal rights
activists and anti-vivisectionists objected to their use. When methods progressed
to using tissue cultures, mistrust of science led people to
object to this method as well. In places like India,
smallpox vaccination had been a routine part of the public
health service since 1947, and yet there were still outbreaks
(41:07):
for decades after that. This led people to claim that
the vaccine was worthless, or even that it was what
had been causing the smallpox. Nations stopped vaccinating people for
smallpox once the disease had been eradicated from within their borders,
and in some people, this just reinforced that perception. Like,
there were no vaccines happening anymore. That must be why
(41:29):
there's no smallpox happening anymore. There were also religious objections
to smallpox vaccinations. Various peoples and cultures interpreted smallpox as
coming from divine will, or interpreted existing methods of smallpox
prevention or treatment as religiously significant. And most of the
last nations to eradicate smallpox were the same ones that
(41:51):
had a long history of being colonized and exploited by
European powers. So people were understandably suspicious of this largely
Western-led public health effort. So the global eradication of smallpox
happened in spite of hesitancy and resistance, not in the
absence of it. So that is how smallpox was finally eradicated.
(42:15):
It does still exist in a couple of labs. There
have been ongoing conversations about destroying those remaining stocks, and
it keeps getting postponed. I would really like it if
we as a global society could get control of the
COVID-19 pandemic, because unless.
Speaker 1 (42:33):
The Carter Center program.
Speaker 2 (42:35):
successfully eradicates guinea worm disease in the immediate future. We
don't have any more eradications of diseases to cover on
this show when I need an optimistic story related to
all this.
Speaker 1 (42:49):
Right. That would be great to report as a history
in the making, but fingers crossed.
Speaker 2 (43:03):
Thanks so much for joining us on this Saturday. If
you'd like to send us a note, our email address
is historypodcast at iheartradio.com. And you can subscribe to the
show on the iHeartRadio app, Apple Podcasts, or wherever you
listen to your favorite shows.
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