Infectious Dose

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 health, climate, and emergency preparedness. The conversation covers COVID-era misinformation, vaccines, measles outbreaks, healthcare access in Texas, and the dismantling of scientific institutions.

The episode also explores the parallels between spaceflight safety systems and high-containment biosafety labs—highlighting why science-based leadership isn’t optional when lives are on the line.

🔗 A full transcript PDF is available in the companion blog post at InfectiousDose.com. And Terry's campaign website is: https://www.terryvirts.com/

Follow Terry: @AstroTerry on Insta/Twitter/Bluesky and astro_terry on Threads

Follow Heather: @pathogenscribe on Insta/Twitter/Bluesky/Threads

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 flu virus so evasive. Plus: how antiviral medications work, why vaccination rates are falling, and what’s coming next in the push for a universal flu vaccine. 

All citations and updates available in companion blog post at infectiousdose.com

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 it means to pause, to stay engaged without burning out, and to carry curiosity into the new year even when certainty feels loud.

The episode closes with a gentle midnight mantra for anyone listening alone, early, or in need of calm at the turn of the year.

Companion blog post at infectiousdose.com

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, present, and yet to come, we trace how tuberculosis was misunderstood, aestheticized, and ultimately revealed as an airborne infectious disease — one that remains among the world’s deadliest today. This episode blends historical storytelling, medical science, and reflection on why some diseases never truly stay in the past.

Because this is a weightier story, we close the episode gathered by the fire for a post-Carol decompression — sharing snacks, drinks, behind-the-scenes thoughts, and space to process the history together.

🕯️ Outbreak After Dark is the after-hours storytelling series of Infectious Dose, where science, history, and a little gothic atmosphere meet. 

This episode is an original reimagining inspired by Charles Dickens’ A Christmas Carol.

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 liver disease and liver cancer later in life. From the biology of the virus to the science behind the birth dose, we explore how this vaccine works, why it’s given so early, and what’s at stake now that ideology is overriding evidence in U.S. vaccine policy.

We also confront a dangerous shift in public health: the dismantling of expert-driven systems in favor of anti-vaccine rhetoric. The result isn’t just political—it’s personal. And it puts newborns at risk.

In this episode:

• How hepatitis B infects the liver and evades the immune system
• Why newborns are uniquely vulnerable to chronic infection
• The history and science behind the universal birth dose
• What the ACIP overhaul means for public trust and public health
• Vaccine safety, ingredients, and long-term effectiveness
• Debunking the most common lies circulating on social media

All citations are in the blog post for this episode at infectiousdose.com

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 evidence, no data, and no scientific analysis. In today’s episode, Heather unpacks what the memo actually said, why experts across the field immediately rejected its conclusions, and how vaccine safety is truly evaluated. She explains the real risks of COVID in kids, from MIS-C to long COVID, and why misinformation from inside federal agencies threatens public trust and puts families at risk. Clear, compassionate, and evidence-driven, this episode gives parents the clarity they deserve.

NOTE: All sources are cited in the blog post for this episode at infectiousdose.com

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, warmth, and cleaning helped communities stay healthier in the harshest season.

Learn how:

• Spices like cinnamon, ginger, and clove helped preserve food and reduce pathogens

• Fires, feasts, and fermentation doubled as primitive infection control

• Cleaning rituals and seasonal isolation slowed the spread of disease

• Modern public health can still draw lessons from these old traditions

We also address how today’s world—sealed homes, global travel, and misinformation—has changed the game, and why clear science is more important than ever.

🎙️ Plus: a discussion of the recent HHS decision under Robert F. Kennedy Jr. to remove the statement “vaccines do not cause autism” from federal pages—and why this political move contradicts decades of scientific evidence.

See the corresponding blog post at infectiousdose.com for all citations.

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-busting, and respect for the communities whose histories were altered by plague long before the feast.

All episode citations and recipes are in the blog post at infectiousdose.com

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 Pestilence: The Global Spread of Antimicrobial Resistance.

NOTE: All cited references are linked in the blog post for this episode at infectiousdose.com

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.

Don't miss today's (Nov 12, 2025) free webinar on RVF: The World Health Organization is hosting a free EPI-WIN webinar at 1pm CET, which is 7pm EST called “Rift Valley Fever and Community Protection: Gaps, Needs and Priorities,” and it brings together experts from WHO, Senegal, and Rwanda.