Antibodies Persist for Infants Born to COVID-19-Vaccinated Moms

TUESDAY, Feb. 15, 2022 (HealthDay News) -- A majority of infants born to COVID-19-vaccinated mothers have persistent anti-spike (anti-S) antibodies at six months, according to a research letter published online Feb. 7 in the Journal of the American Medical Association.

Lydia L. Shook, M.D., from Massachusetts General Hospital in Boston, and colleagues characterized the persistence of vaccine-induced maternal anti-S immunoglobulin G (IgG) in infant blood after maternal vaccination versus natural infection. Individuals who received an mRNA COVID-19 vaccine in pregnancy or who were infected with severe acute respiratory syndrome coronavirus 2 at 20 to 32 weeks of gestation were enrolled (77 and 12 mothers, respectively).

The researchers found that at delivery, vaccinated mothers had significantly higher titers, with a mean optical density of 2.03 compared with 0.65 optical density (OD_{450 to 570}) for mothers after infection. The mean cord titers were also higher after vaccination versus natural infection (2.17 versus 1.00 OD_{450 to 570}). Ninety-eight percent of infants of vaccinated mothers had detectable anti-S IgG at two months. The mean titer at two months was 1.29 OD_{450 to 570} and was correlated with maternal and cord titers at delivery. At six months, 57 versus 8 percent of infants born to vaccinated versus infected mothers had detectable antibodies, with mean titers of 0.33 and 0 OD_{450 to 570}, respectively. There was no correlation seen for maternal nor cord titers with infant anti-S titers at six months.

"Pregnant women are at extremely high risk for serious complications from COVID," a coauthor said in a statement. "And given the lag in development of COVID-19 vaccines for infants, these data should motivate mothers to get vaccinated and even boosted during pregnancy to empower their babies' defenses against COVID."

Two authors disclosed financial ties to the biopharmaceutical and biotechnology industries.

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