Pregnant women infected with COVID-19 infect babies with antibodies: study

Toronto-Women infected with COVID-19 during pregnancy were able to pass antibodies developed through the placenta to the foetation, even if they had no symptoms of infection at that time. Friday.

The study, which also found that mothers did not infect their children in utero, could guide pregnant women’s vaccine trials, the researchers said.

The paper, published by peer-reviewed JAMA Pediatrics, also states that the longer the period between the mother’s catch of the virus and the birth of the newborn, the greater the amount of antibody transferred.

“Our findings indicate the potential of maternal antibodies to protect newborns from SARS-CoV-2 infection and provide information for both newborn management guidance during pregnancy and vaccine trial design. “It helps,” the researchers concluded in the paper, adding that further research is needed. To determine if the antibody was sufficient to protect the newborn from infection.

The study collected maternal and umbilical cord blood for antibody testing from 1,471 mothers and their babies out of a total of 1,714 women who gave birth to Pennsylvania Hospital between April and August 2020. Antibodies to SARS-CoV-2, the virus that causes COVID-19, were found in 83 of 1,471 women, or just under 6%. Of the 83 women who tested positive for the coronavirus, 50, or 60%, showed no symptoms at all.

IgG antibodies that develop after infection or vaccination have been detected in cord blood of 72 of 83 babies born to infected mothers. The migration rate was 1.0 or higher.

“We found a positive correlation between the efficient transfer of IgG antibodies from SARSCoV-2 serum-positive women and antibody levels in the maternal and umbilical cords,” the authors write.

The first IgM antibody that the body makes when fighting a new infection is produced only by the foetation in this case, but was not found in cord blood samples. This indicates that the mother did not infect her child during pregnancy. .. This was true even if the mother was seriously ill. The results are consistent with the latest evidence that it is possible, but rare, to infect babies during pregnancy.

In a sample from 83 mothers and children, 11 babies did not have antibodies to SARS-CoV-2 at birth. Six were born to mothers with very low levels of IgG antibodies. It is the most common antibody in the body and is an antibody that prevents infection. The five were born to mothers who developed only IgM antibodies and did not have IgG antibodies.

The latest findings reveal how the immune response of pregnant women with COVID-19 helps protect infants.

“These babies were potentially unprotected despite documented motherhood infections,” Dr. Flor Munoz, an infectious disease specialist at Baylor College of Medicine, told the study. I am writing in the accompanying editorial.

“If sufficient IgG antibodies are not available for transplacental transfer just before, during, or after delivery, the mother’s infection can be transmitted to the mother or other infected family contacts. Brings a continuous vulnerability to. “

The authors of the paper stated that some of the limitations of their study included the fact that the samples were from only one hospital and only a small number of data on preterm birth could be collected. The larger the sample size, the more you can investigate when the mother became infected during pregnancy and how it affects the transfer of antibodies through the placenta. Scientists also had to rely on medical records that limited their ability to assess COVID-19 symptoms during pregnancy.