Breast Milk May Not Contain COVID-19 Vaccine Traces

A recent study published in the journal JAMA Pediatrics analyzed the breast milk of seven women after receiving mRNA vaccines and found no trace of the vaccine, offers the first direct data of vaccine safety during breastfeeding, stated a UC San Francisco press release.

These researchers found that none of the samples showed detectable levels of vaccine mRNA in any component of the milk.

This limited study's finding could allay concerns among those who have declined COVID-19 vaccination or discontinued breastfeeding.

Research has demonstrated that vaccines with mRNA inhibit transmission of the virus that causes COVID-19. The study analyzed the Pfizer - BioNTech (Comirnaty) and Moderna (SpikeVax) vaccines, both containing mRNA.

“The results strengthen current recommendations that the mRNA vaccines are safe in lactation, and that lactating individuals who receive the COVID vaccine should not stop breastfeeding,” said corresponding author Stephanie L. Gaw, M.D., Ph.D., assistant professor of Maternal-Fetal Medicine at UCSF, in a press statement issued on July 16, 2021.

The study was conducted from December 2020 to February 2021. The mothers’ mean age was 37.8 years, and their children ranging in age from one month to three years. Milk samples were collected before vaccination and at various times up to 48 hours after vaccination.

The study was supported by the Marino Family Foundation, the National Institutes of Health, and others.

UCSF Health has affiliations with hospitals and health organizations throughout the Bay Area in California.