Respiratory syncytial virus (RSV) is a leading cause of hospitalization in infants, responsible for about 25% of their hospital admissions. A recent study published in the Morbidity and Mortality Weekly Report highlights the development of effective prevention strategies that can reduce RSV-related hospitalizations by at least 50% in young infants.
Researchers from Baylor College of Medicine and Texas Children’s Hospital contributed significantly to this study, conducted by the U.S. Centers for Disease Control and Prevention (CDC) through the New Vaccine Surveillance Network (NVSN).
"RSV is a common respiratory virus that causes infections of the lungs and upper respiratory tract," said Dr. Flor M. Muñoz, associate professor at Baylor and Texas Children’s Hospital. "Symptoms can range from mild cold-like illness to severe respiratory disease such as bronchiolitis and pneumonia, requiring hospitalization."
In recent years, two preventive treatments have been developed: a maternal RSV vaccine to protect infants during their first six months via maternal antibodies, and a long-acting monoclonal antibody administered directly to infants aged 0 to 7 months.
“These treatments became available for prevention of severe RSV disease among infants during the 2023-2024 and the 2024–25 RSV seasons," said Dr. Pedro A. Piedra, professor at Baylor.
The study evaluated nearly 20,000 U.S. infants during these periods using data from the RSV-Associated Hospitalization Surveillance Network (RSV-NET) and NVSN.
“This long-awaited study is important because for the first time we are able to see the impact these prevention strategies for RSV have in real life,” Muñoz said.
“We found the greatest impact on the youngest infants, 0 to 2 months old,” Piedra added.
Dr. Vasanthi Avadhanula emphasized timely administration's importance: “The reduction in hospitalizations was most pronounced during the peak RSV season.”
In Houston, later implementation reduced effectiveness compared to other cities where interventions began before the season started. "Having epidemiological data showing when the virus is present... helps decide when to implement these interventions," Avadhanula noted.
“For these RSV protection measures to be effective it’s crucial to follow recommendations for administering... as early as possible in the RSV season,” Piedra advised.
Muñoz highlighted that increasing coverage could further reduce hospitalizations: “Public health efforts should therefore focus on educating healthcare providers and parents about the benefits.”
“Ongoing monitoring... is essential to understand... impact,” Avadhanula concluded.
The NVSN funded by CDC plays a critical role in assessing pediatric viral infections and vaccine impacts across various age groups in children.
Dr. Julie Boom leads NVSN at Texas Children’s Hospital and Baylor College of Medicine. For full contributor details, refer to the publication.
