It’s summer. Pretty soon, drugstores will start advertising that they have flu vaccines, maybe even enticing you with the promise of a coupon to come in and get one. But August is too early in the season for this to be a good idea—unless you are pregnant.
Why most people should get their flu shot in September or October
Flu season tends to start in late fall or early winter, so you want to be protected by the time the influenza virus starts going around. If you get your flu vaccine before Halloween, you’re on track. Whether you get the shot in September or October doesn’t matter much; the CDC says both months are good.
Summer flu shots can make sense for people who don’t think they’ll get a chance to get the shot in the fall; for example, if your kid has their annual checkup every year in August, and you don’t have an easy way of getting them a shot in the fall, you might as well have them get the shot at their checkup. Better early than never, and better early than late.
By the way, if you miss your opportunity and find that it’s November (or December, or January) before you’re able to get the shot, get it anyway. Being protected for the latter half of the season is better than not being protected at all.
Why summer flu shots make sense in your third trimester
If you’re pregnant, and you’re in your first or second trimester, you should still follow the normal guidelines and aim for a September or October flu shot. But if you’re in your third trimester—those last three months of pregnancy—then keep reading.
Babies can’t get a flu shot until they are 6 months old, so a baby born this fall will be vulnerable to catching the flu. (Some vaccines can be effective when given at birth or at very young ages; flu vaccines aren’t one of them.)
But we transfer antibodies to our babies through the placenta in the latter stages of pregnancy, and those antibodies can actually stay with them for the first few weeks to months of life. For this reason, it’s been the recommendation for the last several years that people who are pregnant get a TDaP vaccine in the third trimester of pregnancy, to protect the baby against pertussis (whooping cough) until they can get their own vaccine at 2 months.
The CDC is now extending that recommendation to the flu shot. You should get a TDaP vaccine in your third trimester, no matter the time of year; and you should get a flu shot in your third trimester even if that means getting it in July or August. This way, babies with fall birthdays will be born with antibodies against the flu.