Breastfeeding Antibodies and an Apology

Breastfeeding & Pregnancy Antibodies

As vaccination has expanded we are starting to see increasing vaccine access for pregnant and breastfeeding people. And we’re starting to get evidence on the role of vaccine-produced antibodies in these people. It’s going good!

Breastfeeding We already knew that for people who recover from COVID-19 there are antibodies present in their breastmilk. Now, data from a very very small sample of six people, shows that antibodies are also present in people who are vaccinated. This isn’t surprising given what we know about how vaccines work.

This is cool! And it suggests it is possible breastfeeding infants could get some protection via breastmilk. Whether this will actually translate to infant immunity isn’t yet clear and will not be until we have much more data which actually tests infants for antibodies. I wrote about this a few weeks ago and we’re pretty much at the same place now.

Vaccines give you antibodies. These get into breastmilk. From there, unknown.

To the people who wrote to ask whether they should restart breastfeeding their toddler in response to this after they are vaccinated: unless you are dying to for other reasons, I’d say no.

Pregnancy Vaccination during pregnancy could lead to antibodies to COVID-19 in newborns. Does it?

We have the first evidence on this. It is based on a sample size of one, so it’s more what we’d call a case report. A health care worker received the Moderna vaccine at 36 weeks of pregnancy and her infant was born with antibodies present in her cord blood.

Will this be universal? Will it differ based on when you are vaccinated during pregnancy? How long does it last? We do not know any of these answers yet. We surely will learn them over the next months.

For now I read this as one more plus in the get-the-vaccine-column for pregnant women. It’s a good idea for you, and possibly protective for your infant.