The Food and Drug Administration (FDA) has announced the approval of the first vaccine for pregnant women to prevent respiratory syncytial virus (RSV) in infants. The vaccine, called Abrysvo, has been approved as a maternal vaccine to prevent lower respiratory tract disease (LRTD) in babies from birth through 6 months of age. The single-dose vaccine is administered via injection between 32 and 36 weeks of gestation.
RSV is a common virus that can cause infection of the lungs and respiratory tract, particularly in children. High-risk groups, including infants, older adults, and those with certain medical conditions, are more susceptible to severe illness. RSV is the most frequent cause of lower respiratory tract illness worldwide and the leading cause of infant hospitalization in the United States.
The approval of Abrysvo marks a significant milestone in public health, as it is the first and only maternal vaccine that can immediately protect newborns from RSV. The vaccine has shown promising results in clinical studies, with over 81% reduced risk of severe LRTD within the first three months of birth compared to a placebo.
Pregnant women who receive the vaccine may experience mild side effects such as muscle pain, headache, nausea, and pain at the injection site. However, there was a slightly higher occurrence of certain complications, including preeclampsia, low birth weight, preterm birth, and jaundice in infants of mothers who received Abrysvo compared to the placebo group.
Pfizer, the manufacturer of Abrysvo, expressed its excitement about achieving the goal of delivering a maternal vaccine to protect infants during their most vulnerable months. The company's chief scientific officer of vaccine research and development, Annaliesa Anderson, emphasized the significance of the approval in preventing serious consequences from RSV in newborns.
This fall, expectant parents may have another option to protect their newborns from RSV as Pfizer's Abrysvo vaccine expands its approval to include pregnant women. The vaccine provides immunity to pregnant women, which can be passed on to their babies before birth, offering protection in the infant's earliest months of life. The FDA's approval followed positive results from clinical studies, demonstrating the vaccine's efficacy in reducing the risk of severe LRTD in babies up to six months old.
The Centers for Disease Control and Prevention (CDC) will need to review the FDA's approval and update its recommendations for maternal vaccines. While doctors are not legally obligated to follow the CDC's recommendations, they play a crucial role in determining insurance coverage requirements for vaccines.
The approval of Abrysvo adds another option to protect newborns from RSV, alongside nirsevimab, marketed as Beyfortus. The CDC had previously recommended Beyfortus for babies born during their first RSV season this fall and winter. However, the CDC's Advisory Committee on Immunization Practices will review the impact of Abrysvo's approval on their recommendations. Preliminary calculations suggest that issuing recommendations for both vaccines may not be cost-effective, and the CDC may prioritize Abrysvo as the primary option.
There have been concerns about a few cases of very rare preterm births in babies whose mothers received Abrysvo during pregnancy. While the number of cases in Pfizer's trial was not statistically significant, there was a larger increase in preterm births that led to the suspension of a separate RSV vaccine trial by GSK. The CDC and FDA committees have discussed the potential link between the vaccine and preterm births, and Pfizer plans to continue monitoring the vaccine's safety through real-world data.
Overall, the approval of Abrysvo as a maternal vaccine for RSV prevention represents a significant advancement in protecting newborns from this common and potentially severe illness. The vaccine offers hope for expectant parents and the scientific community as they strive to promote the health and well-being of infants during their first months of life.
