COVID-19 Vaccinated Moms Pass Antibody Protection To Breastfeeding Newborns

The JAMA Network published results from a prospective cohort study on April 12, 2021, conducted with breastfeeding women who chose to be vaccinated in Israel between December 23, 2020, and January 15, 2021.

This study found robust secretion of SARS-CoV-2 specific IgA and IgG antibodies in breast milk for 6 weeks after vaccination.

And no mother or infant experienced any serious adverse event during the study period.

All 84 study participants received 2 doses of the Pfizer-BioNTech COVID-19 vaccine 21 days apart.

Mean levels of anti–SARS-CoV-2-specific IgA antibodies in the breast milk increased rapidly and were significantly elevated at 2 weeks after the first vaccine (2.05 ratio; P < .001), when 61.8% of samples tested positive, increasing to 86.1% at week 4 (1 week after the second vaccine).

Mean levels remained elevated for the duration of follow-up, and at week six, 65.7% of samples tested positive. Anti–SARS-CoV-2-specific IgG antibodies remained low for the first 3 weeks, with an increase at week 4 (20.5 U/mL; P = .004), when 91.7% of samples tested positive, increasing to 97% at weeks 5 and 6.

Corresponding Author: Ilan Youngster, MD, MMSc, Pediatric Infectious Diseases Unit and the Center for Microbiome Research, Shamir Medical Center, Zerifin 70300, Israel (youngsteri@shamir.gov.il).