On this week's show, we discuss what the endgame of the pandemic will be. It likely isn't herd immunity. And if herd immunity isn't the goal, does that change how people should behave once they're vaccinated? We have a science-backed guide for how to evaluate what's risky and what's safe among the vaccinated.

Coronavirus mutations have complicated our path forward. But that doesn't mean that our current plan out of the pandemic is futile.

Should you take a leftover vaccine? Should you pass up a vaccine if you think you don't need it as much as someone else does? We talk to bioethicists to get their answers on these questions and more.

Anna talks with Dr. Margaret Liu, one of the pioneers of gene-based vaccines, about vaccines that use mRNA to help us build immunity to COVID-19, including the Pfizer-BioNTech and Moderna vaccines. How is this method different from vaccines in the past, and what does the mRNA do once it gets inside our bodies?

There are so many questions about a COVID-19 vaccine that we didn't know where to begin. So we began with you! We took to the mailbag to find answers on vaccine availability, immunity, and more.

On the first day of Christmas, PODCAST-19 gave to me ... an interview with Dr. Fauci.

Dr. Anthony Fauci stops by the pod to talk about post-vaccine life, the new variant of the virus in the U.K. and which celebrity he'd like to see vaccinated.

Data has been such a valuable commodity during the pandemic. Unfortunately, at times data has been in short supply, because US government agencies haven't always undertaken national data collection efforts. So what happens when individuals citizens try to collect data themselves? We talk to Professor Emily Oster, who developed a national COVID-19 School Response Dashboard, to find out what she's learned about COVID in schools, the implications of volunteers developing their own public health trackers, and how she thinks the Biden administration will approach pandemic data collection.

It feels like a cure for this pandemic may be in sight. But for many people, injecting a brand-new scientific discovery into their body won't sit well. So, how are scientists making sure that a COVID-19 vaccine won't cause more damage than the disease? How do regulators decide what an acceptable side effect is? And what would happen if someone did have a serious reaction to the COVID vaccine after it was released? This week, we're devoting our whole show to vaccine safety.

Our producer, Sinduja Srinivasan, reports on long COVID, and how our health care system might cope with so many patients with ongoing symptoms.

This week, Pfizer announced that its coronavirus vaccine may be more than 90 percent effective. Anna and FiveThirtyEight's senior science writer, Maggie Koerth, discuss what we know (and don't know) about about the vaccine.