Create a Website Account - Manage notification subscriptions, save form progress and more.
September 6, 2023
RSV is an RNA virus, and transmission occurs primarily via respiratory droplets when a person coughs or sneezes, or through direct contact with a contaminated surface. Infants, young children, and older adults, especially those with chronic medical conditions, are at increased risk of severe disease from RSV infection. CDC estimates that every year RSV causes approximately 58,000–80,000 hospitalizations (1,2) and 100–300 deaths (3,4) in children ages <5 years, as well as 60,000–160,000 hospitalizations (5,6) and 6,000–10,000 deaths (3,4,7) among adults ages 65 years and older.
In the United States, the annual RSV season has historically started in the fall and peaked in winter. However, this pattern was disrupted during the COVID-19 pandemic, likely due to public health measures to reduce the spread of COVID-19 that also reduced the spread of RSV. RSV activity was limited between May 2020 and March 2021, followed by an atypical season with onset in May 2021 that peaked in July and August and continued through the end of 2021 (8). In 2022, RSV activity began in the summer, peaking across the United States in October and November, and rapidly declining by winter. Despite the disruptions in timing, RSV activity continued its geographic pattern of starting in Florida and the southeast before spreading to northern and western parts of the continental United States in 2021 and 2022.
In recent weeks, CDC has observed an increase in RSV activity in parts of the Southeastern United States. Nationally, the weekly percentage of positive detections reported to the National Respiratory and Enteric Virus Surveillance System (NREVSS), a national laboratory-based surveillance network, has remained below the season onset threshold of polymerase chain reaction (PCR) test positivity of 3.0% for 2 consecutive weeks. However, NREVSS data show increases in weekly PCR positivity above 3.0% in Florida beginning in the week ending July 22, 2023, and the 3-week moving average of PCR positivity has been greater than 5.0% for the past 4 weeks. More robust data are available through Florida’s sentinel surveillance, which also shows PCR positivity just under 5.0% for the most recent week. In Georgia, CDC has also observed an increase in rates of RSV-associated hospitalizations reported to RSV-NET, a population-based surveillance system. Among children ages <4 years, RSV-associated hospitalization rates increased from 2.0 hospitalizations per 100,000 population for the week ending August 5, 2023, to 7.0 hospitalizations per 100,000 population for the week ending August 19, 2023, with the majority occurring among infants ages <1 year. Due to reporting delays, surveillance data may be less complete in the 2 most recent weeks.
In 2023, new prevention tools for RSV have become available.
A clinician’s recommendation is one of the most important factors in whether patients choose to accept a prevention product or vaccine. As we head into respiratory virus season this fall, it’s important to understand new prevention tools, recommend them to patients who could benefit, and use them effectively to prevent severe RSV disease.
CDC recommends nirsevimab for the following groups:
Dosage of nirsevimab: All infants ages <8 months:
Infants and children ages 8–19 months who are at increased risk for severe RSV disease:
Another prevention product, palivizumab (Synagis®, SobiTM), is available for children <24 months of age with certain conditions that place them at increased risk for severe RSV disease. Where nirsevimab is not available during this RSV season, the American Academy of Pediatrics (AAP) recommends that eligible infants and older babies should continue to receive palivizumab until nirsevimab becomes available.
See full CDC HAN Health Alert for additional information and references