How Much COVID Protection Will My Baby Get from Breastfeeding?

I wasn’t planning to breastfeed for a variety of reasons, but my COVID vaccine got rescheduled for when I am 37 weeks pregnant. Now I’m worried the baby won’t get protection from the vaccine. Is there enough evidence that breastfeeding helps confer COVID protection that I should change my plan and do so just for that reason?

—COVID Stressed

We generally think it takes two to four weeks to develop and pass on antibodies. A vaccine at 37 weeks is cutting it close, but you may well get some good antibodies passed along.

Our evidence on the impact of breastfeeding on COVID is limited at best. In principle, antibodies could be passed indirectly through breast milk. I’ve heard some experts note this is most likely for very early breastfeeding, when infants tend to get milk all over their faces — the antibodies are therefore more accessible in the mucus membranes. However, we do not have any systematic evidence that breastfeeding is protective against COVID-19. If it is, the impacts are likely very small.

Whether this changes your breastfeeding plan or not depends, I suppose, on how close you feel to the line. If you were close to indifferent, I could see this pushing toward a few weeks of nursing. If you’re set on using formula (which is how I read your letter), then I don’t see how this small possible benefit would change that.