Perl SH, Uzan-Yulzari A, Klainer H, et al. - A national vaccination program was initiated in Israel on December 20, 2020, against COVID-19. Researchers herein examined if maternal immunization results in secretion of SARS-CoV-2 antibodies into breast milk as well as investigated any potential adverse events among women and their infants. In this prospective cohort study, a convenience sample of breastfeeding women (either exclusive or partial) belonging to vaccine-target groups who chose to be vaccinated were recruited through advertisements and social media. Two doses of the Pfizer-BioNTech vaccine were administered to all the participants 21 days apart. The study was completed by 84 women, providing 504 breast milk samples. Analyses revealed robust secretion of SARS-CoV-2 specific IgA and IgG antibodies in breast milk for 6 weeks after vaccination. They detected IgA secretion as early as 2 weeks after vaccination; this was followed by a spike in IgG after 4 weeks (a week after the second vaccine). Similar findings are reported in few other studies in women infected with COVID-19. They identified strong neutralizing effects of antibodies detected in breast milk of these women, indicating a potential protective effect against infection in the infant.