What are the chances of getting a vaccine's side effects?

U.K. warns EU of reputation damage if it reneges on vaccines Biggest floods in decades hamper Australia's vaccine rollout Contentious hunt for Covid's origin points to China animal trade How common are vaccine side effects? In this week's edition of the Covid Q&A, we look at vaccine side effects.  In hopes of making this very confusing time just a little less so, each week Bloomberg Prognosis is picking one question sent in by readers and putting it to an expert in the field. This week's question comes to us from Zongheng in the Bay Area of California. Like many people, Zongheng is concerned about potential side-effects from the vaccines. Zongheng asks:  What is the possibility of getting serious side effects from a vaccine? There's no medical intervention that doesn't carry some risk of side effects. Even the warning label on a bottle of ibuprofen lists some pretty scary potential outcomes. But serious side effects from taking an Advil or two to quell a headache are extremely rare. The same is true for Covid-19 vaccines.  "The broadest-stroke answer is that the risk of a serious side effect is so low that we are not actually sure that the 'side effect' is actually a due to the vaccine or whether it is something that would have happened anyway because people are people," says Sarah Fortune, an immunologist at the Harvard T.H. Chan School of Public Health. In other words, if you track enough people, some are bound to have medical issues, and sometimes it can be hard to tell whether those issues were caused by a vaccine or something else. For example, in the Moderna clinical trials, similar numbers of people experienced serious side effects in both the group that got the vaccine and the group that received a placebo. That suggests there were very few serious side effects related to the vaccine, if any.  In Moderna clinical trials, similar numbers of people experienced serious side effects in the both the group that received the vaccine and the group that got the placebo.  Photographer: Stephen Zenner/Bloomberg To date, Covid-19 vaccines have been given to more than 100 million people in the U.S., with priority for those who were older and already had health issues. Some had serious medical events shortly after receiving the vaccine. But there's no way of knowing whether the vaccine was to blame in any one individual case, says Fortune. The odds, she says, suggest it's highly unlikely.  "We know the risk of bad outcomes associated with coronavirus infection, and it is thousands to tens of thousands of times higher than the risk" of any potential side effect from a vaccine. It's all about those kinds of risk calculations.  "It is this calculus that leads public health leaders to say that there is no question, you should get vaccinated," Fortune says.  Thanks to all of you for writing in this week! Next Sunday, we'll be answering the best question we receive again. So if you have any, we want to hear from you. Write to us at CovidQs@bloomberg.net — Kristen V. Brown  Track the virus When Will We Reach Herd Immunity? It's a complicated question and the subject of debate. Anthony Fauci has said that vaccinating 70% to 85% of the U.S. population would be required. However, on a global scale, that's a daunting level of vaccination. Save the Date | Bloomberg New Economy Conversations with Andrew Browne: Big Pharma joined with governments to deliver vaccines in record time. The successful moonshot could spur future research into other affordable drugs. Join us March 23 at 10 a.m. EDT when Katalin Karikó, senior vice president of vaccine pioneer BioNTech, and others discuss Vaccine Miracles and the New Promise of Science. Register here. What you should read How Latin America Rebounds From Recession   Better fiscal policy is needed to ensure a sustained recovery. BioNTech CEO: Lockdowns to Wane in Summer In the U.S. and Europe, at least. UAE Expands Vaccine to Ages 16 and Over The country has inoculated the majority of those at risk. Netanyahu Campaigns on Vaccine Obsession Polls suggest it hasn't swung the election in his favor. German Covid Rate Hits Two-Month High Crossing a key threshold may trigger new restrictions. Know someone else who would like this newsletter? Have them sign up here. Have any questions, concerns, or news tips on Covid-19 news? Get in touch or help us cover the story. Like this newsletter? Subscribe for unlimited access to trusted, data-based journalism in 120 countries around the world and gain expert analysis from exclusive daily newsletters, The Bloomberg Open and The Bloomberg Close. Follow Us Get the newsletter You received this message because you are subscribed to Bloomberg's Coronavirus Daily newsletter. Unsubscribe | Bloomberg.com | Contact Us Bloomberg L.P. 731 Lexington, New York, NY, 10022