Several studies have already indicated that pregnant women who have contracted Covid-19 transmit neutralizing antibodies against the Coronavirus to their fetuses.
This circumstance is not simply anecdotal, but it supposes a argument in favor of those who advocate vaccinating pregnant women since the immunization obtained could be double: that of the mothers and those of their future children.
“Higher levels of maternal antibodies are associated with passive neonatal immunity,” concluded a study conducted by American scientists and published last month in the American Journal of Obstetrics and Gynecology.
“These studies will ultimately inform the scientific community about the potential benefit of maternal vaccination against SARS-CoV-2”, The scientists add in their conclusions.
The scientists, led by Dr. Yawei Jenny Yang, from the Weill Cornell School of Medical Science in New York, analyzed blood samples from 88 women who had passed the Covid and gave birth during the first wave of the pandemic and their children , verifying that 78 of the 88 neonates also had neutralizing antibodies.
Lack of data on Covid vaccines and pregnant women
The transmission of antibodies to fetuses by pregnant women is an already known circumstance in the case of other common diseases such as influenza or whooping cough, as is the vaccination of pregnant women to immunize them and their newborns against to these types of pathogens.
However, clinical trials with Covid-19 vaccines conducted to date they have not been able to count on enough pregnant women, partly because of the difficulties in finding volunteers willing to participate, and in fully evaluating the potential risks.
“Currently it is not being vaccinated not because it is contraindicated, but because it is simply not studied and it is not in the technical data sheet,” explains Dr. Ruth Figueroa, president of the Vaccine Study Group of the Spanish Society of Infectious Diseases and Clinical Microbiology ( Seimc).
In addition, recalls Figueroa, the fact that the vast majority of pregnant women who have experienced Covid-19 have done so asymptomatically -although it also increases the risk of suffering the disease in a serious way-, has meant that they have not been considered a priority in this first phase of the immunization process.
No risks are foreseen
The pharmaceutical company Pfizer, which distributes the vaccine produced by the German laboratory BioNTech, began a clinical trial last week with 4,000 pregnant women in nine countries, including Spain.
In addition to studying the evolution of women, all of them between weeks 24 and 34 of gestation, the study also check the health effects of babies when they are born and if, indeed, the mothers have transmitted the antibodies to them.
In any case, even if it remains to be proven empirically, there is nothing to suggest that the currently approved vaccines may have specific risks for pregnant women.
“By vaccination logic, although it must be demonstrated, as no live attenuated virus is administered with these vaccines, which are the only contraindicated vaccines in pregnancy, such as measles or chickenpox, it must be assumed that these do not affect the woman or the fetus “, says Dr. Fernando Moraga-Llop, vice president of the Association Spanish of Vaccination.
For Moraga-Llop, the most advisable, for the moment, is to limit vaccination to pregnant women who belong to risk groups, either due to comorbidities or occupational exposure, as in the case of health workers.