Outbreaks of respiratory syncytial virus (RSV) cases last spring and earlier than expected this fall have strained medical resources across the country, adding to concerns about hospital bed availability for the remainder of the winter cold and flu season.

However, experts say that by mid-winter, when RSV cases typically peak, the spread of the virus appears to be declining.

Adam J. Ratner, M.D., of Hassenfeld Children's Hospital in Longueuil, N.Y.U., noted:-"The RSV season early this year was really impressive." While different parts of the country have seen a surge in RSV, nationally the virus appears to be showing up early in 2022 almost everywhere.

Typically, RSV causes 58,000 to 80,000 hospitalizations per year in children 5 years old and younger in the United States. In addition, the virus is thought to cause approximately 2 million outpatient visits and 100 to 300 deaths in children under 5 years of age

The Centers for Disease Control and Prevention reports that so far, in 2022-2023, there have been an average of about 43.4 RSV-related hospitalizations per 100,000 people Based on previous studies, typically the majority of RSV-related hospitalizations are in children under the age of 1 It is too early to end the RSV season, but weekly case totals reported by the CDC suggest early cases have risen significantly from previous years.

For example, the CDC counted nearly 42,000 RSV cases between October and November 2021. In comparison, more than 126,000 cases were identified between October and November 2022. However, the data also show that while RSV cases began to rise earlier in the year, they began to decline from early December 2022, more than a month earlier than the previous year

This earlier-than-normal peak has prompted public health experts to provide new guidance on managing RSV, particularly in high-risk infants.In November, the American Academy of Pediatrics (AAP) updated its recommendations for the use of palivizumab to prevent severe RSV cases.

Citing the decline in RSV infections during the COVID-19 pandemic and subsequent significant changes in seasonal epidemiology, the AAP revealed that additional doses (beyond the typical 5 consecutive doses) of palivizumab may be needed to provide adequate protection. the AAP noted that there is no evidence that additional doses or doses of palivizumab given at higher frequencies result in adverse effects. A number of immunization protocols also continue to be investigated to help reduce the burden of RSV in future seasons.