The Centers for Disease Control and Prevention (CDC) yesterday sent a health alert to clinicians, warning that respiratory syncytial virus (RSV) activity is rising in parts of the Southeast, which typically predicts the spread of the virus to other part of the country.
In its Health Alert Network notice, the CDC said RSV activity continues to resume its seasonal pattern, following earlier disruptions from COVID-19 measures such as social distancing and masking, which limited the spread of a range of respiratory viruses. Even during the initial COVID years, however, the CDC said RSV activity maintained its geographic pattern, starting in Florida and elsewhere in the Southeast before spreading to other parts of the country.
Infants, young children, and seniors are at highest risk of severe disease. The CDC estimates that each year RSV hospitalizes 58,000 to 80,000 kids younger than 5 years and results in 100 to 300 deaths. Among seniors, it said severe RSV infection leads to 60,000 to 160,000 hospitalizations each year, along with 6,000 to 10,000 deaths.
Recent rises in Florida, Georgia
RSV test positivity in Florida rose above the seasonal threshold in the week ending July 22 and has remained above the mark over the past 4 weeks, the CDC said.
Meanwhile, Georgia has reported an increase in RSV-related hospitalizations. In children younger than 4 years old, the rate rose from 2 hospitalizations per 100,000 population in the first week of August to 7 per 100,000 hospitalizations by the middle of August, with babies younger than 1 year old bearing the biggest burden.
The CDC said it expects RSV activity to spread north and west over the next 2 to 3 months.
New tools to protect young children, seniors
With RSV activity poised to spread to other US regions, the CDC urged clinicians to get ready to use newly approved RSV prevention tools.
In early August, the CDC signed off on a recommendation for a long-acting monoclonal antibody vaccine called nirsevimab for protecting infants in their first RSV season and other young children in risk groups against severe RSV illness. The CDC urged clinicians to start offering the shot, marketed as Beyfortus by Sanofi and AstraZeneca, as soon as it is available, which is expected by early October.
Until then, another monoclonal antibody preventive called palivizumab is available for certain children younger than 2 years old who have underlying conditions such as preterm birth with chronic lung disease that put them at higher risk for severe RSV infection.
Also, the CDC reminded healthcare providers about the two newly available RSV vaccines, Arexvy from Pfizer and Abrysvo from Pfizer. The vaccines are recommended for protecting adults ages 60 and older from severe RSV disease, based on shared decision making between clinicians and patients.
In August, the Food and Drug Administration approved Pfizer's vaccine for use in pregnant women from 32 to 36 weeks gestation as a strategy for protecting their infants against the virus. The CDC's vaccine advisory committee, however, has not yet discussed a policy recommendation.
CDC and FDA will continue to monitor the safety and effectiveness of RSV vaccines and nirsevimab.
"CDC and FDA will continue to monitor the safety and effectiveness of RSV vaccines and nirsevimab, review data as collected, keep the public informed of findings, and use data to make recommendations—consistent with standard practices for all immunization products," the CDC said.