Research reveals compromised transfer of SARS-CoV-2-specific antibodies through placenta

New Delhi, Dec 25 (ANI): Recent analyses indicate that pregnant women and newborns may face elevated risks of developing more severe cases of COVID-19 following SARS-CoV-2 infection. New research led by investigators at Massachusetts General Hospital (MGH) and published in Cell reveals lower than expected transfer of protective SARS-CoV-2 antibodies via the placenta from mothers who are infected in the third trimester. The cause may be alterations to these antibodies after they're produced--a process called glycosylation. The results expand on the team's recent findings published in JAMA Network Open that pregnant women with COVID-19 pass no SARS-CoV-2 virus, but also relatively low levels of antibodies against it, to newborns. For this latest study, the scientists compared maternal antibodies against the flu (influenza), whooping cough (pertussis), and SARS-CoV-2, and how these antibodies transferred across the placenta. Influenza- and pertussis-specific antibodies were actively transferred in a relatively normal fashion. In contrast, transfer of SARS-CoV-2-specific antibodies to the baby was not only significantly reduced, but the antibodies transferred were less functional than the antibodies against influenza. The reduced transfer was only observed in third trimester infection. The scientists found that altered attachments of carbohydrates to the SARS-CoV-2-specific antibodies -- a process called glycosylation -- may be to blame for this reduced transfer from mother to fetus in the third trimester.