Impact of maternal SARS-CoV-2 booster vaccination on blood and breastmilk antibodies

• Published in: PloS one Vol. 18; no. 6; p. e0287103
• Main Authors: Rick, Anne-Marie, Lentscher, Anthony, Xu, Lingqing, Wilkins, Maris S, Nasser, Amro, Tuttle, Dylan J, Megli, Christina, Marques, Ernesto T A, McElroy, Anita K, Williams, John V, Martin, Judith M
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 13.06.2023; Public Library of Science (PLoS)
• Subjects: Antibodies; Antibodies, Viral; Babies; Biology and Life Sciences; Blood; Breast milk; COVID-19 - prevention & control; COVID-19 Vaccines; Durability; Female; Health aspects; Humans; Immunization; Immunoglobulin A; Immunoglobulin G; Infant; Infants; Infections; Lactation; Medicine and Health Sciences; Milk; Milk, Human; People and Places; Pregnancy; Prospective Studies; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Statistical analysis; Vaccination; Vaccines; Viral antibodies; Women; United States
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0287103

Maternal COVID-19 vaccination could protect infants who are ineligible for vaccine through antibody transfer during pregnancy and lactation. We measured the quantity and durability of SARS-CoV-2 antibodies in human milk and infant blood before and after maternal booster vaccination. Prospective cohort of lactating women immunized with primary and booster COVID-19 vaccines during pregnancy or lactation and their infants. Milk and blood samples from October 2021 to April 2022 were included. Anti-nucleoprotein (NP) and anti-receptor binding domain (RBD) IgG and IgA in maternal milk and maternal and infant blood were measured and compared longitudinally after maternal booster vaccine. Forty-five lactating women and their infants provided samples. 58% of women were anti-NP negative and 42% were positive on their first blood sample prior to booster vaccine. Anti-RBD IgG and IgA in milk remained significantly increased through 120-170 days after booster vaccine and did not differ by maternal NP status. Anti-RBD IgG and IgA did not increase in infant blood after maternal booster. Of infants born to women vaccinated in pregnancy, 74% still had positive serum anti-RBD IgG measured on average 5 months after delivery. Infant to maternal IgG ratio was highest for infants exposed to maternal primary vaccine during the second trimester compared to third trimester (0.85 versus 0.29; p<0.001). Maternal COVID-19 primary and booster vaccine resulted in robust and long-lasting transplacental and milk antibodies. These antibodies may provide important protection against SARS-CoV-2 during the first six months of life.