NEW YORK: Researchers at the Department of Obstetrics and Gynaecology, New York University (NYU) Langone Health, New York, recently found COVID antibodies in the umbilical cord blood of neonates of vaccinated mothers.
Megan E. Trostle, the lead author of the research, and colleagues analysed both anti-N and anti-S IgG, i.e. antibodies to nucleocapsid and spike proteins, respectively, in the cord blood of vaccinated women. It is contrary to existing studies which analyse anti-S IgG alone.
Anti-S IgG may produce after natural infection or vaccination, whereas anti-N IgG is present after a natural illness.
In this study, the researchers included those pregnant women who had received at least one dose of the mRNA COVID-19 vaccine. All the subjects had received two doses of vaccine except one. They collected the umbilical cord blood thirty-six deliveries and analysed anti-N IgG via Abbott SARS-CoV-2 assay and anti-S IgG via Elecsys anti-SARS-CoV-2 assay.
The results show high titres of anti-S IgG in the cord blood of 36 neonates whose mother had completed their vaccine series on average 13 weeks before delivery. The mothers of two neonates with the lowest titre, i.e., <250 U/ml, had received their second dose more than 20 weeks before delivery. The 31 samples out of 36 were also tested for anti-N IgG, and all came negative. The neonate of the mother who had received a single dose was also positive for anti-S IgG.
The study concludes that the robust cord blood levels suggest a high degree of vertical transmission of these antibodies might protect the infant in the neonatal period. The study didn’t obtain the neonatal and maternal blood antibody levels to associate, but the correlation becomes less clinically relevant due to high antibodies levels in cord blood.
The research “High antibody levels in cord blood from pregnant women vaccinated against COVID-19” has recently been published online in the American Journal of Obstetrics & Gynecology MFM.