Welcome to Season 3, a Public Health On Call, a podcast from the Johns Hopkins Bloomberg School of Public Health.

I'm Josh 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.

Hi, I'm Lindsay Smith Rogers, producer of Public Health On Call.

Today, Stephanie Desmond talks to Dan Salman, a Johns Hopkins vaccine expert, about how

some governments in Europe suspended AstraZeneca's COVID-19 vaccine last week when a tiny

fraction of people reported dangerous blood clots after receiving it. They discuss how exactly

scientists determine whether there's an actual link between the two or whether the

cases just happened. They also discuss how experts make decisions around safety with vaccines.

Just a note that this conversation was recorded on March 17th and that since then,

the European Medicines Agency has concluded that the vaccine's benefits outweigh the risks.

Let's listen.

Dan Salman, thanks so much for joining me. Thanks for having me.

So today I'd like to talk about what's in the news, which is the AstraZeneca COVID-19 vaccine.

Several European countries have suspended its use because there have been some links, they think,

to blood clots in people who've had the vaccine. My understanding is that of 17 million people in the EU and the UK who received the vaccine, 37 had blood clots in the brain. So talk to me about

what that means to you as someone who studies

vaccine safety. So I would address this a couple ways. And let me just say I've only seen

...