Do I Need Another COVID Booster While Pregnant?

I am 20 weeks pregnant and trying to determine whether to get the COVID booster at the end of my second trimester, as has been recommended by you and others. I’m fully vaccinated with two boosters already, but want to ensure as much potential protection for my baby as possible. My issue is that I have reacted strongly to each previous COVID vaccination received (fever, flu-like symptoms), but the symptoms typically pass within 24 hours. Are these symptoms dangerous for a developing baby? It’s one thing to get sick incidentally (I have a toddler in preschool, so colds and whatnot are common), but I do feel hesitant about knowingly having strong vaccine reactions while pregnant. Hoping you may be able to offer some guidance or reassurance — I haven’t read anything in the literature to help guide my decision here. Thank you very much for all that you do!
—Caitlin

To start and review: The reason for a COVID booster at the end of the second trimester is to provide some post-birth protection for your child. For the same reason we do a Tdap shot at that time, it ramps up your antibodies, which are passed to your child and provide some protection for the first few months (until they can get vaccinated). Kids are in general at low risk from COVID, but the risk for infants is higher (as it is with virtually all illnesses). Studies have shown that kids whose moms got antibodies during pregnancy are less likely to be hospitalized. So there are reasons to do it.

On the flip side is your concern about fever from the reaction. The concern with fever is a risk of birth defects, but this is largely about the first trimester. Moreover, even that link is not well supported in the data. In my view, the best study is here — it’s large and followed women over time — focused on a cohort of 100,000 women in Denmark. The data includes about 8,000 women who had a fever during early pregnancy. The researchers see no link with birth defects.

Bottom line: There isn’t any reason to worry about the vaccine reaction at this point, and there are reasons to do it.

For those of you who have other questions about COVID, especially given the official end of the COVID emergency, I wrote about the state of affairs going forward in this post.