RSV

Respiratory syncytial virus, also called RSV, is a common respiratory virus that usually causes cold-like symptoms. Most people infected with RSV will experience mild illness and typically recover within one to two weeks. However, infants and young children, older adults, adults with chronic heart or lung disease, adults living in nursing homes and long-term care facilities, and immunocompromised people are at higher risk for severe illness from RSV infection. RSV can also lead to more severe infections, such as pneumonia (an infection of the lungs) and bronchiolitis (inflammation of the small airways in the lung). It is estimated that RSV causes approximately 60,000–160,000 hospitalizations and 6,000–10,000 deaths among older adults.

RSV season generally starts during the fall and peaks in the winter. RSV is very contagious and can spread in several ways: through exposure to respiratory droplets when an infected person coughs or sneezes, through direct contact with an infected person, or by touching a contaminated surface with RSV. People infected with RSV tend to show symptoms within four to six days after exposure. Symptoms of RSV may include runny nose, decrease in appetite, coughing, sneezing, fever, and wheezing.

People infected with RSV are typically contagious for three to eight days and may become contagious a day or two before showing signs of illness. Infants and immunocompromised people infected with RSV can continue to spread the virus even after they stop showing symptoms for as long as four weeks.

There are various tests available that confirm RSV infection, all of which are administered by a healthcare professional. Contact your local health care provider if you have questions about RSV or RSV testing. 

Added June 29, 2023 

On June 29 2023, the CDC recommended two new RSV vaccines for adults age 60 and up. The single-dose vaccines—one developed by Pfizer (called Abrysvo) and the other developed by GSK (called Arexvy)—were determined to be equally effective by the CDC Advisory Committee on Immunization Practices (ACIP) after reviewing results from clinical trials. The vaccines are expected to be available to the public this fall when RSV typically begins to circulate at higher levels.

Once the vaccines are available, adults age 60 and up will be eligible to receive an RSV vaccine after consulting with their health care provider.

Added June 29, 2023 

On August 3, 2023, the CDC approved and recommended the use of nirsevimab (Beyfortus)—a new monoclonal antibody treatment for infants and toddlers to protect against severe illness caused by RSV. Monoclonal antibodies are proteins that mimic the antibodies that our bodies naturally produce. While there is not currently an approved pediatric vaccine, monoclonal antibody treatments–like Beyfortus–provide an extra layer of defense that helps fight RSV infections and protect infants’ lungs. 

Beyfortus is expected to be available for fall 2023–when the RSV season begins. One dose of Beyfortus can protect infants for five months, the length of an average RSV season. The treatment has been shown to reduce the risk of both hospitalizations and healthcare visits for RSV in infants by about 80%. A dose of Beyfortus is recommended for:

• All infants younger than eight months in their first RSV season 
• Children between the ages of eight months and 19 months who are at increased risk of severe RSV disease, such as severely immunocompromised children, in their second RSV season. 

In addition to Beyfortus, there is another monoclonal antibody treatment to help protect infants and young children from severe RSV infection. This treatment is called palivizumab (Synagis). Synagis is currently available, but only recommended for infants and young children with certain health conditions who are at high risk for severe RSV infection. Synagis injections must be given monthly during RSV season (typically fall through spring) to provide increased protection.

These products are not treatments for a child who already has an infection. Caregivers to young children are encouraged to contact their health care provider to see if Synagis or Beyfortus should be used as a preventive measure for their child.

Added August 9, 2023 

Pfizer has developed and conducted safety and efficacy trials of a single-dose RSV vaccine for pregnant women. The results from clinical trials are promising and are currently under review for approval. If the vaccine is approved by the FDA and CDC, it may be available as soon as fall 2023.

The vaccine would be administered between 32 and 36 weeks of pregnancy, which would then trigger the development of antibodies that would be passed on to the newborn. These antibodies would provide protection for about the first six months of the baby’s life when they’re extremely vulnerable to infections like RSV.

Expectant families are encouraged to contact their respective obstetricians for further information on the availability and accessibility of this vaccine.

Updated September 8, 2023