April 07, 2026
Alexandre Contador/UNSPLASH.COM
Respiratory syncytial virus, which is particularly dangerous to infants and babies, is spreading at higher levels than normal this spring. Pennsylvania and New Jersey are among states that have extended their windows for immunizations.
Because respiratory syncytial virus is spreading at unusually high levels for this time of year, Pennsylvania and New Jersey have extended their window for infants and toddlers be immunized against RSV through April 30.
RSV is a common respiratory illness that most children get by age 2 and recover from without complications. But RSV can be dangerous for premature infants and babies under 12 months. About 2-3% of infants under 3 months are hospitalized each year due to the virus, the Centers for Disease Control and Prevention says.
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"RSV peaked later than usual this year, and many areas of the country are continuing to see (emergency department) visits and hospitalizations linger into spring," Dr. Susan Kansagra, chief medical officer for the Association of State and Territorial Health Officials, told CNN Monday. "Given this ongoing transmission, health departments are looking at their local data, and many are recommending that providers continue monoclonal antibody administration into April."
The American Academy of Pediatrics recommends monoclonal antibody shots for infants whose mothers did not receive the RSV vaccine while pregnant. The vaccine gives babies immediate protection against the virus and lasts five months or longer. The CDC recommends women receive the RSV vaccine during the third trimester of pregnancy.
Typically, RSV infections start in the fall and peak during the winter, leveling out by early spring. But with the virus still circulating at unusually high levels this year, 48 jurisdictions (states, territories or cities) have lengthened the opportunity for eligible infants and toddlers to be immunized through April 30.
Philadelphia has extended its window through April 15, but is monitoring the situation and may end up joining Pennsylvania in extending through April 30, the Association of Immunization Managers says. AIM is a public health organization of state, local and territorial leaders of immunization programs trying to increase immunization rates against preventable diseases.
The RSV vaccine also is recommended for older adults and people with compromised immune systems and other health issues.
Common symptoms of RSV include runny nose, cough, sore throat, sneezing and headache. Severe cases in infants and babies that require hospitalization may include short, shallow rapid breathing, poor feeding, lethargy, fever and other symptoms, the Mayo Clinic says.
