Welcome to Season 2 of Public Health On Call, a podcast from the Johns Hopkins

Bloomberg School of Public Health.

I'm Joshua Sharfstein, Vice Dean for Public Health Practice and Community Engagement,

and a former secretary of Maryland's Health Department.

Our goal is to bring scientific evidence and experience to the public health news of the day

through informative interviews with scientists, community leaders, policy experts, public health

officials, clinicians, and more. If you have ideas or questions for us to cover, please email us at

Public Health Question at jhhhu.edu. That's public health question at jhhu.edu for future podcast

episodes. Today, I speak to Dr. Ruth Karen, a professor of international health at the Johns

Hopkins Bloomberg School of Public Health.

Dr. Karen is also one of the top vaccine experts in the world.

In recent years, she has served on key vaccine committees for the U.S. Centers for Disease Control and Prevention and for the World Health Organization.

She has also chaired the major vaccine advisory committee to the U.S. Food and Drug Administration.

In our conversation, she answers a long list of important questions about COVID vaccines.

Let's listen.

Dr. Karen, thank you so much for joining me.

It would be great if you could introduce yourself

to our listeners, starting maybe with how long

you've been working as a vaccine scientist.

Yeah, so I've been working on vaccines

for probably about two and a half decades.

I'm a pediatrician and also trained in infectious diseases and

...