RSV Prefusion F Vaccine in Pregnancy Not Linked to Preterm Birth

A recent study has found that prenatal vaccination with a nonadjuvanted bivalent respiratory syncytial virus (RSV) prefusion F (RSVpreF) protein subunit vaccine does not increase the risk of preterm birth (PTB). This research, published on July 8 in JAMA Network Open, was led by Dr. Moeun Son from Weill Cornell Medical College in New York City.

The study was a retrospective observational cohort investigation that aimed to explore the relationship between RSV vaccination during pregnancy and perinatal outcomes. The research included data from 2,973 pregnant individuals, of which 34.5 percent received the prenatal RSVpreF vaccine.

Researchers observed that among those who had the prenatal vaccination, 60 patients experienced preterm birth. In comparison, 131 individuals without the vaccination showed evidence of preterm birth, corresponding to 5.9 percent and 6.7 percent, respectively. This indicates no significant increase in the risk of preterm birth associated with prenatal vaccination, even after adjusting for potential confounding factors and addressing immortal time bias.

Furthermore, the study found no significant differences in pregnancy and neonatal outcomes based on vaccination status. Nevertheless, an increased risk of hypertensive disorders of pregnancy was noted when analyzed through a time-dependent model.

The authors of the study concluded that there were no substantial differences in maternal or perinatal outcomes between those who had electronic health records showing evidence of receiving the prenatal RSVpreF vaccination and those who did not.

It should be noted that two of the authors disclosed connections with Pfizer, the manufacturer of the RSVpreF vaccine. This disclosure is important for maintaining transparency and understanding potential influences or biases in the study.

In summary, the findings suggest that the prenatal RSVpreF vaccine is safe regarding the risk of preterm birth and does not significantly alter pregnancy or neonatal outcomes, though caution may be warranted concerning hypertensive disorders of pregnancy.