Infectious Dose

When we talk about misinformation in public health, we usually imagine social media, conspiracy theories, or individuals misunderstanding science. But what if some of the most influential misinformation starts somewhere else?

In this episode of Infectious Dose, Heather speaks with biomedical researcher Dr. Mark Ungrin about how scientific ideas move thr...

Mpox isn’t just a headline from 2022.

In this episode, we explore what scientists have learned about mpox since the global outbreak — from how the virus moves through the body to why its lesions can be so painful. We break down the biology of orthopoxviruses, the surprising role of human immune enzymes in shaping viral evolution, and the emergence of ...

What if attraction isn’t entirely yours? In this Outbreak After Dark episode, Heather, Kate, and Sam gather around the campfire to explore the parasites, fungi, and viruses that manipulate behavior in the name of survival. We’re talking:

• Toxoplasma gondii, the parasite that dampens rodents’ fear of cats
• The lancet liver fluke, which turns ants into grazing bait
• Ophiocordyceps, the real-life “zombie ant” fungus
• Baculoviruses th...

Nipah virus scares virologists, and for good reason. It infects endothelial cells and neurons. It can cause fatal encephalitis. It spreads from bats to humans, and sometimes between people. So why does it keep burning out? In this episode of Infectious Dose, we examine:

• Henipavirus biology and receptor usage (eph...

Syphilis is back—and it never really left. In this episode, we break down how a curable, preventable infection is resurging to cause a public health crisis across the U.S., and globally, especially among pregnant people and newborns. We unpack the science behind Treponema pallidum, the public health failures driving the crisis, and why trust in health systems is still broken—from Tuskegee to ...

This short, standalone episode is a statement of ethics.

It explains why this podcast will not remain silent in the face of state violence, the dismantling of public health, and the normalization of harm against vulnerable people. It clarifies the ethical boundaries that guide the work behind Infectious Dose: that science is for everyone, but cruelty, authoritarianism, and the protection of abuse are not neutral positions.

This epi...

RSV is one of the most common respiratory viruses — and a leading cause of hospitalization in young children worldwide.

In this solo episode, I explain what RSV is, how it spreads, and what illness typically looks like in babies, children, and adults. We cover when RSV can be managed at home, how to recognize breathing-related red flags, when to go to...

Spiders inspire some of our deepest fears—but are they actually as dangerous as we think? In this Outbreak After Dark episode, Heather, Sam, and Kate dig into the real science behind spiders, venom, and so-called “spider bites,” separating evidence from exaggeration. Along the way, they unpack persistent myths, medical misattribution, and why spiders loom so large in outbreak lore—despite rarel...

What are biological weapons—and what are they not?

In this episode, Heather is joined by bio-risk consultant and biodefense researcher Conor Browne for a grounded, reality-based conversation about biological weapons, biodefense, and why public discourse around these topics so often goes wrong.

Together, they unpack what actually defines a biological weapon, why intent and delivery matter, and how real historical programs differ fro...

In this episode of Infectious Dose, Heather McSharry talks with Terry Virts—retired NASA astronaut, Air Force colonel, and candidate for Congress in Texas—about what happens when leadership ignores science.

Drawing on his experience in aviation, spaceflight, and risk analysis, Terry discusses the real-world consequences of sidelining evidence in public ...

This week in “Seasonal, Not Safe,” we confront the truth about influenza in 2025–2026. It’s not “just the flu.” From the tragic stories of children lost to fast-moving infections, to the science of how influenza spreads, mutates, and turns deadly — this episode explores what’s really happening this season. We break down the rise of Subclade K, current global flu patterns, new U.S. vaccine policy controversies, and what makes the fl...

This New Year’s Eve episode isn’t about resolutions — it’s about a reset.

In Still Curious: A New Year’s Reset (Without Resolutions), Heather reflects on a difficult year for science, public health, and trust, and makes the case for curiosity as a quieter, steadier way forward. Rather than focusing on optimism or big promises, this episode explores what i...

This month’s Outbreak After Dark is a special holiday episode — and a heavier one.

In A Consumption Christmas Carol , we reimagine Dickens’ classic ghost story through the real epidemic that haunted Victorian London: tuberculosis. Long before antibiotics, TB shaped daily life, art, poverty, and policy — romanticized in parlors, devastating in tenements, and deadly across all social classes.

Guided by familiar spirits of past, prese...

This episode was updated in March 2026 to explicitly frame the hepatitis B birth dose controversy through a systems-level lens — examining how evidence-based vaccine policy can be destabilized when institutional safeguards are removed, and why recognizing those failures is essential to restoring public trust.

This episode unpacks everything you need to know about hepatitis B and the life-saving vaccine that helps prevent chronic l...

This episode was updated in March 2026 to clarify that the analysis presented already reflects the systems-level framework used throughout this vaccine safety series — examining what the claim gets right, where institutional safeguards failed, and what evidence would actually be required to support the claims being made. 

A leaked FDA memo sparked headlines claiming the COVID vaccine killed children — but the memo included no evide...

There’s more to your favorite winter rituals than nostalgia.

In this episode, we dive into how centuries of winter traditions—across Europe, Asia, Africa, and the Americas—offered accidental protection against infectious diseases. From citrus in stockings to cloves in mulled wine, from kimchi to candlelight, we trace how ancient practices around food, air...

In this Outbreak After Dark episode, we revisit Thanksgiving’s origin story through the lens of infectious disease. Heather, Sam, and Kate dive into the epidemics that devastated Indigenous nations before the Pilgrims ever arrived, the microbial mismatches between Old World and New, and the narratives that still distort how we talk about “the First Thanksgiving.” It’s a campfire conversation that blends history, science, myth-busti...

This week’s episode dives into the roots of the global antimicrobial resistance crisis. How did routine cuts, UTIs, and pneumonias become untreatable? What systems helped superbugs evolve — and why is the problem accelerating worldwide?

We explore the science, the policies, the failures, and the future of drug-resistant microbes in A Prescription for Pest...

Rift Valley fever is back — and it’s hitting harder than it has in years. In this episode, we trace the 2025 outbreak from Mauritania to Senegal, explore how the virus hides between rainy seasons, and reveal what scientists have learned from unexpected hotspots in Tanzania. From mosquitoes and livestock to people and policy, this is Rift Valley fever: when the rains bring life and loss.