Respiratory Syncytial Virus (RSV)
What is Respiratory Syncytial Virus (RSV)?
Respiratory syncytial virus (RSV) is a common respiratory virus that can cause cold-like symptoms or more severe illness like pneumonia. RSV usually spreads seasonally in the fall and winter, along with influenza (flu) and COVID-19. This virus can be particularly dangerous for infants, older adults, and those with compromised immune systems. RSV can lead to bronchiolitis (inflammation of the small airways in the lungs) and pneumonia (infection of the lungs).
Fortunately, we have tools to combat RSV, including maternal vaccines, vaccines for older adults, and monoclonal antibodies for infants who did not receive protection through maternal vaccination, as well as young children at increased risk for severe disease entering their second RSV season.
On this page, you can explore how RSV spreads, who is at risk, what the symptoms are, and how to prevent RSV.
mostchildren will get an RSV infection
How does RSV spread?
RSV is contagious and can be spread directly through coughs or sneezes from an infected person, which can lead to droplets that enter another person’s eyes, nose, or mouth.
RSV can also be spread through direct contact like kissing the face of a child with RSV, or indirectly by touching a surface that has the virus on it and then touching your face before washing your hands. Read more about transmission here.
Anyone can contract RSV.
Most children will get an RSV infection by the time they are 2 years old. Some children are at higher risk for severe RSV disease, including premature infants and those with chronic lung disease, congenital heart disease, cystic fibrosis, or weakened immune systems. In older adults, especially those aged 75 years and older, RSV can cause severe disease. RSV can also be serious for adults with chronic health conditions such as heart or lung disease or a weakened immune system.
RSV can spread easily through respiratory droplets and direct contact with an infected person.
What are the symptoms of RSV?
Common symptoms of RSV include:
- Fever
- Runny or stuffy nose
- Coughing
- Difficulty breathing
- Shortness of breath
- Wheezing
- Sneezing
- Decreased appetite
In very young infants, the only symptoms of RSV may be irritability, decreased activity, and apnea (pauses in breathing lasting more than 10 seconds). These require immediate medical attention.
How do you prevent RSV?
We now have tools to prevent RSV in the most high-risk groups: infants and older adults.
Infants & Maternal
There are two options to protect infants against RSV, and most infants will only need one.
The first option is a maternal vaccination that is given between weeks 32 through 36 of pregnancy during RSV season (September through January in most of the U.S.). This maternal vaccination helps protect newborns for approximately six months after birth.
There are also preventive monoclonal antibodies (mAbs) that are available for infants. A mAb is given as a shot and provides protection for at least five months. mAbs are recommended for infants younger than 8 months old during their first RSV season and high-risk young children aged 8 to 19 months during their second RSV season. Two mAbs products are currently available in the U.S.: nirsevimab and clesrovimab.
Adults
It is recommended that all adults aged 75 years and older receive a single dose of the adult RSV vaccine.
A single dose of the adult RSV vaccine is also recommended for those aged 50–74 years who are at increased risk for severe RSV disease. This includes those with certain chronic medical conditions, moderate or severe weakened immune systems, and individuals living in nursing homes. Adults who have already received one dose of an RSV vaccine do not need an additional dose at this time, as RSV vaccination is not currently recommended annually.
Recommended Vaccination Schedules
To ensure that your family is up to date on their vaccines, view or download the childhood and adult immunization schedules and talk to your healthcare provider.
RSV can be particularly severe in premature infants, infants younger than 6 months old, and young children with pre-existing health conditions. However, 80% of children younger than 2 years of age who are hospitalized with RSV do not have risk factors. In the U.S., RSV is the leading cause of hospitalization in children younger than one year old. Learn more about RSV in infants and young children.
Each year RSV results in approximately 60,000–160,000 hospitalizations and 6,000–10,000 deaths among adults over 65 years in the U.S. Those at highest risk of severe outcomes related to RSV include older adults with chronic heart or lung disease, and/or weakened immune systems.
If someone is sick and has difficulty breathing, they need to seek medical attention right away. Additional warning signs include blue lips or face, irritability, decreased activity, decreased appetite, and apnea (temporary stopping of breathing). RSV can lead to bronchiolitis (inflammation in the small airways in the lung) and pneumonia (infection in the lung).
A monoclonal antibody (mAb) is not a vaccine. Vaccines work by introducing a weakened, killed, or part of a germ into your body that causes your body to make antibodies so that you can fight off any future infections and/or severe illnesses. Monoclonal antibodies are antibodies that are directly introduced into your body and provide short-term protection against RSV.
