WASHINGTON (AP) — The Food and Drug Administration (FDA) has commenced a safety review of two injectable drugs from Merck and Sanofi aimed at protecting babies and toddlers from respiratory syncytial virus (RSV). This virus is known to send thousands of American children to the hospital each year. These drugs, designed as long-acting antibody treatments rather than vaccines, have come under scrutiny as health officials reassess routine vaccination strategies for children under the oversight of Health Secretary Robert F. Kennedy Jr.

Although the FDA describes the inquiry as a routine safety evaluation, it reflects growing concerns surrounding childhood vaccination protocols. A representative from the FDA indicated that product labeling may be updated based on the findings of this review. Both Merck and Sanofi have stated that they have not observed new safety signals related to their medications, which were recently approved for infants and young children vulnerable to RSV.

The injectable treatments act as laboratory-created versions of natural antibodies, bolstering the immune system’s ability to combat RSV. While vaccines have already been approved for older patients and pregnant women, these injections serve as the primary defense against RSV for infants during the virus's seasonal outbreaks.

Merck's injectable drug, Enflonsia, is specifically approved to protect infants in their first RSV season, which typically spans five months. The company maintains transparency and is committed to a thorough review of its clinical data. Sanofi's Beyfortus, on the other hand, claims no new safety issues have arisen, having accumulated considerable evidence from over 50 studies involving more than six million immunized babies worldwide.

While RSV may cause mild symptoms in most healthy children, it poses life-threatening risks to the very young and elderly. In light of recent recommendations from the CDC, the antibody shots are advised for infants born just prior to or during the RSV season, especially if their mothers did not receive the necessary vaccinations late in pregnancy. Additionally, high-risk infants aged 8 to 19 months may also benefit from the treatment.

The review aligns with broader discussions about childhood vaccinations as Kennedy’s administration has prompted changes, including a controversial recommendation to cease routine hepatitis B vaccinations for newborns, stimulating criticism from various medical and scientific communities. As the FDA continues to examine vaccine safety more rigorously, including COVID-19 vaccinations, the future of immunization policies remains uncertain.