Information published last Friday (01/29) in the periodical JAMA Pediatrics suggest that people infected with the new coronavirus during pregnancy can generate natural immunity for their babies by transferring it through the placenta.
In addition, the earlier the contamination occurs, the greater the amount of antibodies present in the babies, according to the research. This possibly reveals the ideal time for the administration of vaccines, since the substances would offer more benefits to babies; when applied in the early stages of pregnancy.
Scott E. Hensley, an associate professor of microbiology at the University of Pennsylvania Perelman School of Medicine and a leading author of the study, told the The New York Times that the findings are quite consistent with what is known about the behavior of the human organism in relation to other viruses.
In any case, the analysis of approaches related to immunization programs still needs to be concluded, according to Hensley.
Babies receive covid-19 antibodies through the placenta, study shows.Source: Unsplash
More than 1,500 patients who gave birth at the Pennsylvania Hospital in Philadelphia between April and August last year underwent tests, and 83 had antibodies against covid-19. Of that amount, 72 babies also tested positive for the presence of immunity, regardless of whether the people who generated them had symptoms.
What’s more, half of the children had antibody levels as high as or even higher than those found in the blood of the organisms in which they grew up. A quarter of the samples even had a concentration of 1.5 to 2 times higher than the “original”. “This is very efficient,” said Karen Puopolo, an associate professor of pediatrics at the University of Pennsylvania and one of the study’s senior authors.
The antibodies that crossed the placenta were precisely those that are believed to offer long-term protection, those of immunoglobulin G, or IgG, generated days after infection. Those related to immunoglobulin M, or IgM, in turn, detected after an infection, were absent in all samples, that is, the babies would not have been sick.
Immunity would be even more pronounced than in the “original” organism.Source: Unsplash
One question that hangs in the air is whether this would be enough to prevent newborns from being infected after delivery (and the fact that some of them are born prematurely puts the permanence of immunity in check over time). For this reason, those responsible for the research highlight the need to replicate the method in other institutions.
Denise Jamieson, an obstetrician at Emory University in Atlanta and a member of the group of experts in covid-19 of the American College of Obstetricians and Gynecologists, characterizes the placenta as a complex and poorly studied organ. In this sense, Andrea G. Edlow, assistant professor of Obstetrics, Gynecology and Reproductive Biology at the Harvard Medical School, argues that the expansion of studies in the area is fundamental for understanding the complete scenario.
“What we really want to know is whether antibodies in the vaccine cross the placenta efficiently and protect the baby, similar to what happens in flu and whooping cough,” said Jamieson.
“Additional research is necessary”, defend experts.Source: Unsplash
A closer look
Part of the lack of knowledge about the mechanisms for generating protection in pregnant people and their babies is mainly due to the exclusion of this public from initial clinical trials of vaccines around the world, something that experts say they have to change.
For Mark Turrentine, also from the American College of Obstetricians and Gynecologists, the question shows how much to consider this cut is essential: “particularly when the benefit of vaccination is greater than the potential risk of a life-threatening disease”, he concludes.