Answering Your Questions About the COVID-19 Vaccine

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Q. Can the side effects of the COVID-19 vaccine be worse than the disease?

A. The vaccine is definitely not riskier than the disease it prevents, but it can cause side effects. One is an allergic reaction called anaphylaxis. It occurs in only two out of 10,000 people, right after getting the shot. That's why they ask you to wait for 15 or 30 minutes before heading home: health professionals at the vaccination site have the medicines to successfully treat the rare allergic reaction. Much less severe side effects are more common, such as a sore arm, rashes, body aches, fever, and fatigue, particularly after the second (booster) shot for the two-dose vaccines. And a small number of people who've received the Johnson & Johnson vaccine or the AstraZeneca vaccine (given outside the United States) have experienced a rare and dangerous blood clotting disorder. But is the vaccine worse than the disease? Here are some numbers to consider. In people over age 60, the chance of dying from the disease is 3%; over age 75, the chance of dying is 11%. In contrast, only one out of every one million fully vaccinated people in the United States has caught COVID-19 and died, despite being vaccinated. So the vaccines aren't perfect, but they're as close to perfection as you get in the real world.

Q. Is it true that the mRNA vaccines used for COVID-19 might alter my genes?

A. The mRNA vaccines do not alter or affect your genes in any way. As we discussed in the March 2021 issue, the mRNA vaccines are like all vaccines: they cause several parts of your immune system to attack the virus, if the virus ever enters your body. They do it as well as or better than traditional vaccines, and they can be developed more rapidly.

Q. Will we need a COVID-19 booster shot in the future?

A. We might: it depends on whether the vaccines protect us for a long time -- which we can't predict with confidence -- and on whether the virus develops variants that the current vaccines can't fight as well as they do the first strains of the virus. But I doubt we'll need a booster shot every year, as we do for the flu.

Q. Why did it take nearly a year to get a vaccine against COVID-19?

A. Developing several safe and effective vaccines against a brand-new virus in just under a year was not a failure: it was a triumph. Previously, no vaccine to a brand-new virus had been developed in less than four years. The thousands of scientists and co-workers who made it happen deserve our gratitude, not our impatience.