Maternal COVID-19 vaccine timing and antibody concentrations in infants born preterm

In this prospective study of 220 pregnant individuals with preterm and full-term deliveries, receipt of three or more compared with two doses of COVID-19 vaccine before delivery resulted in 10-fold higher cord anti-Spike antibody levels.

Maternal antibody concentration appeared more important than delivery gestational age in determining cord anti-Spike antibody levels. The number of doses and timing considerations for COVID-19 vaccine in pregnancy should include individuals at risk for preterm delivery. The study is published in JAMA Network.

COVID-19 vaccine–derived antibodies in pregnant people may protect infants from severe infection in the first 6 months of life via transplacental antibody transfer. Few data exist on maternally derived SARS-CoV-2 antibodies in preterm compared with full-term infants in association with vaccination timing.

A total of 220 participants with 36 preterm and 184 full-term deliveries were studied. Before delivery, 121 persons received 2 vaccine doses and 99 persons received 3 or more vaccine doses. The geometric mean concentration of maternal anti-S antibodies was 674 after 2 doses and 8159 after 3 or more doses The cord anti-S antibody geometric mean concentration was 1000 after 2 doses and 9992 after 3 or more doses After adjustment for vaccine timing and number of doses before delivery, no association was found between preterm delivery and cord anti-S antibody levels.

In this prospective cohort study of pregnant individuals with preterm and full-term deliveries, receipt of 3 or more compared with 2 doses of COVID-19 vaccine before delivery resulted in 10-fold higher cord anti-S antibody levels. Maternal antibody concentration appeared more important than delivery gestational age in determining cord anti-S antibody levels. The number of doses and timing considerations for COVID-19 vaccine in pregnancy should include individuals at risk for preterm delivery.

Reference: Timing of maternal COVID-19 vaccine and antibody concentrations in infants born preterm; JAMA NETWORK