SARS-CoV-2 infection increases risk of COVID-19 infection in pregnant women, newborns

Recent studies show that pregnant women and newborns may be at higher risks of developing more severe cases of COVID-19 after SARS-CoV-2 infection.

New research led by researchers at Massachusetts General Hospital (MGH) and published in Cell showing lower-than-expected movement of SARS-CoV-2 immune antibodies through the placenta from infected mothers in the third trimester. Perhaps the reason is changes in these antibodies after they have been removed – a process called glycosylation.

The findings expand on the team’s recently published results in Open JAMA Network not only do pregnant women with COVID-19 pass the 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 influenza (flu), whooping cough (pertussis), and SARS-CoV-2, and how these antibodies passed over their ‘placenta.

Flu and pertussis-specific antibodies have been actively mobilized in a very conventional fashion. In contrast, not only was the reduction of SARS-CoV-2-specific antibodies to the infant significantly reduced, but the antibodies transmitted were less functional than the influenza antibodies . The reduced movement was seen only in the third trimester disease.

The scientists found that this reduced migration from mother to fetus in the third trimester may be due to altered carbohydrate binding to the specific antibodies SARS-CoV-2 – a process called glycosylation. The carbohydrate binding on specific SARS-CoV-2 antibodies in maternal blood was different from those seen on specific antibodies with influenza and pertussis.

This carbohydrate pattern may cause the specific COVID antibodies to be “stuck” in maternal circulation, rather than being transmitted through the placenta through placental antibody receptors.

Infection-induced elevation in total maternal antibodies, as well as elevated placental expression of an antibody receptor that attracts a carbohydrate pattern on the specific SARS-CoV-2 antibodies, helped to overcome the problem to level and enables the transfer of some active antibodies from mother to fetus.

Interestingly, some of the best-moving antibodies were also the most active, active killer cells that could help the new baby fight the virus if exposed.

The findings have an impact on the design of SARS-CoV-2 vaccines for pregnant women.

Vaccine management capable of driving high levels of COVID-specific antibodies with placenta-preferred glycosylation patterns for selective transfer to the fetus may lead to better neonatal and child protection. “

Andrea Edlow, MD, MSc, Co-Senior Research and Authora Fetal Medicine Specialist, Massachusetts General Hospital

Edlow is too is assistant professor of Obstetrics, Gynecology, and Regenerative Biology at Harvard School of Medicine.

The co-author and Founding Member of the Ragon Institute of MGH, MIT and Harvard, Galit Alter, PhD, notes: “We are beginning to define the rules of placental antibody movement of SARS-CoV-2 for the first time – capturing our ability to rationally design vaccines to protect pregnant women and their newborns. “

In addition, an understanding of how antibody movement changes according to trimester may indicate critical windows in pregnancy that may be eligible for vaccination to provide the best protection for both mother and her mother. a child.