HealthDay News — A recent study published online on November 6 in the American Journal of Obstetrics & Gynecology reveals that administering the respiratory syncytial virus (RSV) vaccine to expectant mothers at least five weeks before their due date significantly enhances the transplacental transfer of vital maternal antibodies to their newborns.
Led by Olyvia J. Jasset and her team from the prestigious Vincent Center for Reproductive Biology at Massachusetts General Hospital in Boston, this research investigated the impact of gestational age at the time of vaccination and the interval between maternal RSV vaccination and delivery on the transfer of maternal antibodies. The study involved a prospective cohort of 124 pregnant individuals who received the RSV vaccine during their pregnancy, with antibody levels meticulously measured in the umbilical cord at delivery and in the peripheral blood of infants at the age of two months.
The findings demonstrated that maternal vaccination against RSV resulted in considerably elevated levels of both maternal and cord anti-RSV F antibodies when compared to those who experienced natural RSV infection. Notably, the researchers observed significantly lower cord:maternal transfer ratios in instances where maternal vaccination occurred two to three weeks or three to four weeks prior to delivery, in contrast to those vaccinated more than five weeks beforehand. This pattern persisted with pertussis vaccination given before 30 weeks of gestation, where transfer ratios were also significantly diminished at two to three or three to four weeks as opposed to those vaccinated over four weeks prior to delivery.
“The finding of optimal transplacental transfer of maternal antibody at ≥5 weeks postvaccination may inform future evaluations of vaccine timing,” the authors emphasized, highlighting the importance of timing in vaccination strategies.
Two authors involved in the study have disclosed connections to the pharmaceutical industry, raising potential questions regarding conflicts of interest in the research.
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What are the key benefits of receiving the RSV vaccine during pregnancy, according to Dr. Jasset’s study?
**Interview with Dr. Olyvia J. Jasset on Maternal RSV Vaccination Study**
**Interviewer:** Thank you for joining us today, Dr. Jasset. Your recent study published in the *American Journal of Obstetrics & Gynecology* has garnered significant attention. Can you explain the main findings regarding the RSV vaccine for expectant mothers?
**Dr. Jasset:** Thank you for having me. Our study focused on the timing of RSV vaccination in pregnant women. We found that when expectant mothers receive the RSV vaccine at least five weeks before their due date, there is a marked increase in the transfer of protective antibodies to their newborns. This transplacental transfer is crucial for providing early immunity to infants, especially given the potential severity of RSV infections in this vulnerable population.
**Interviewer:** That sounds promising for both mothers and infants. How does this immunity benefit newborns directly after birth?
**Dr. Jasset:** Newborns have immature immune systems and rely heavily on maternal antibodies for protection against infections, including respiratory syncytial virus. By ensuring that these antibodies are passed through the placenta in higher quantities, we effectively enhance the newborn’s ability to fend off RSV during the first few months of life, which is when they are most at risk.
**Interviewer:** We have seen recent recommendations regarding the administration of monoclonal antibodies like nirsevimab for infants. How does your study intersect with these recommendations?
**Dr. Jasset:** Our findings complement the recommendations for administering monoclonal antibodies like nirsevimab, especially for infants whose mothers didn’t receive the RSV vaccine during pregnancy. Nirsevimab is effective in preventing RSV, but improving maternal antibody transfer through vaccination provides an additional layer of protection for the infant. If mothers are vaccinated appropriately, we can potentially reduce the reliance on monoclonal antibodies and lower the risk of severe RSV illness in their newborns [[1](https://www.acog.org/clinical-information/physician-faqs/maternal-rsv-vaccination)].
**Interviewer:** With the growing availability of RSV vaccines, how can expectant mothers ensure they get vaccinated in time?
**Dr. Jasset:** It’s crucial for expectant mothers to discuss RSV vaccination with their healthcare providers as early as possible during their prenatal visits. Many pharmacies and healthcare systems are beginning to offer RSV vaccines, but timing is key. We recommend that vaccinations occur at least five weeks before the expected delivery date to maximize antibody transfer to the newborn [[1](https://www.acog.org/clinical-information/physician-faqs/maternal-rsv-vaccination)].
**Interviewer:** Thank you, Dr. Jasset, for sharing these important insights. Your research is vital for improving the health of newborns in the face of RSV.
**Dr. Jasset:** Thank you for having me. It’s an exciting time for maternal and infant health, and I hope our study encourages more pregnant women to get vaccinated and protect their little ones.