Study Finds Vaccinated Mother’s Breast Milk Contains COVID-19 Antibodies

A recent study has suggested that mothers vaccinated against COVID-19 may pass along protection against the virus through nursing.

The study published by the University of Florida says antibodies passed through the breast milk of vaccinated mothers could be beneficial to babies. However, further research is needed to measure its impact.

“A lot of moms, pregnant women, are afraid to get vaccinated. They want to do what’s best for their babies,” said Dr. Josef Neu, a co-author of the study and professor in the UF College of Medicine Department of Pediatrics and Division of Neonatology. “This is something that we wanted to know whether it may actually provide some benefit.”

Joseph Larkin III, a senior author of the study and associate professor in the university’s Department of Microbiology and Cell Science said since babies are born with undeveloped immune systems and too young to get the vaccine, breast milk from vaccinated mothers can be altered to potentially improve their vulnerability.

“Milk is a dynamic substance. So in other words, what the baby and the mom (are) exposed to in the environment, there are changes in the milk that correspond to these environmental conditions,” Neu said. “And these can then specifically help the baby.”

The University of Florida started their study in December of last year when the vaccines were first available to health care workers.

The school used the blood and breast milk of 21 lactating mothers who worked in health care and volunteered to participate in the study. The mothers had never had the virus and were eligible to receive the vaccine.

Researchers discovered that in breast milk specifically, after the second dose, there was a pronounced 100-fold increase of immunoglobulin A antibodies, Larkin said. The antibodies remain present even if the breastmilk is frozen and stored.

Other studies surrounding pregnant women have shown that antibodies produced by vaccinated pregnant women are passed to the fetus through the umbilical cord blood.

“By just them becoming vaccinated, they are already helping the baby,” Larkin said.