Respiratory Syncytial Virus (RSV)

What is Respiratory Syncytial Virus?

Respiratory Syncytial (sin-SISH-uhl) Virus (RSV), is a common respiratory virus that usually causes mild, cold-like symptoms including runny nose, cough, sneezing, and fever. Typically, it affects the upper airways, but can involve the lungs and breathing passages.

Who gets Respiratory Syncytial Virus?

Anyone can be infected with RSV at any age and more than once in a lifetime. Most of the time, RSV infections in children and adults are not serious and resolve on their own. However, RSV can be serious, especially in infants, some young children, older adults, and older adults with underlying illnesses. People at increased risk of severe RSV illness include very young infants, premature babies, young children with lung or heart diseases, older adults, older adults with heart or lung disease, and people with a weakened immune system.

RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia (infection of the lungs) in children younger than one year of age in the United States. Almost all children will have an RSV infection by their second birthday.

What are the symptoms of Respiratory Syncytial Virus?

The symptoms of RSV usually appear in stages and not all at once. Symptoms of RSV infection usually include:

Runny nose
Decrease in appetite
Coughing
Sneezing
Fever
Wheezing

In very young infants with RSV, the only symptoms may be irritability, decreased activity, and breathing difficulties. Out of every one hundred infants who get RSV, about 2-3 of them will need to be hospitalized. Older adults with a more severe case of RSV may have difficulty breathing or worsening of an underlying heart or lung disease. This may result in hospitalization. Call your healthcare provider if you or your child is having difficulty breathing, not drinking enough fluids, or experiencing worsening symptoms.

How soon after exposure do symptoms appear?

Individuals infected with RSV usually show symptoms within four to six days after becoming infected.

One of the first signs of a more serious illness can be rapid breathing or a cough with wheezing. It means that the virus has spread to the lower respiratory tract (the lungs). This can lead to inflammation of the small airways in the lungs (bronchiolitis) or a lung infection (pneumonia).

How is Respiratory Syncytial Virus spread?

RSV can spread from person to person in the following ways:

When an infected person coughs or sneezes
You get virus droplets from a cough or sneeze in your eyes, nose, or mouth
You have direct contact with the virus, like kissing the face of a child infected with RSV
You touch a surface that has the virus on it (such as a doorknob) and then touch your nose, mouth, or eyes before washing your hands

Individuals infected with RSV are usually contagious for three to eight days and may become contagious a day or two before they start showing signs of illness. However, some infants, and people with weakened immune systems, can continue to spread the virus even after they stop showing symptoms, for as long as four weeks. RSV can survive for many hours on hard surfaces (such as tables, crib rails, doorknobs). However, it typically lives on soft surfaces (such as tissues and hands) for shorter amounts of time.

How is Respiratory Syncytial Virus diagnosed?

RSV infection can be confirmed using different types of tests performed at a doctor’s office. Typically, the inside of the nose is swabbed and this is tested for the virus.

What is the treatment for Respiratory Syncytial Virus?

Currently, there is no specific treatment for RSV infection, but researchers are working to find medications that will fight the virus. In children and adults, most RSV infections go away on their own in a week or two. People with RSV can be treated at home with rest, fever-reducing medication (such as acetaminophen or ibuprofen) and drinking plenty of fluids. Never give aspirin to children as a medication to reduce fever or pain. Talk with your healthcare provider before giving your child nonprescription cold medicines, as some of these medicines contain ingredients that may not be good for children. In older adults, especially those who take other medicines, it is a good idea to check with the doctor about which nonprescription medicines can be used safely.

Call your healthcare provider if you or your child is having difficulty breathing, not drinking enough fluids, or experiencing worsening symptoms.

How can Respiratory Syncytial Virus be prevented?

Take the following steps to prevent the spread of RSV, specifically if you have cold-like symptoms:

Stay at home when you are sick and avoid contact with others, especially children and others who are at for severe RSV disease.
Cover coughs and sneezes with a tissue or your upper shirt sleeve
Wash your hands often with soap and water for at least 20 seconds
Avoid close contact such as kissing, shaking hands, sharing cups, and eating utensils with others
Clean frequently touched surfaces such as toys, doorknobs, and mobile devices often

Immunizations are available to protect against severe RSV disease in specific groups of people.

Vaccines for Adults Aged 60 and Over

All adults aged 75 years and older are recommended to receive a single dose of one RSV vaccine (Arexvy or Abrysvo).
Adults aged 60-74 years who have chronic heart or lung disease, a weakened immune system, live in a nursing home or long-term care facility, or have certain other medical conditions may be at increased risk of severe RSV.
RSV is not an annual vaccine. Adults who have previously received a dose of an RSV vaccine are NOT recommended to receive another dose at this time.
Eligible adults can get an RSV vaccine at any time, but the best time to get vaccinated is in late summer and early fall before RSV usually starts to spread in the community.

Immunizations to Protect Infants

Pregnant People
- People who are 32 through 36 weeks pregnant during September through January should get one dose of the maternal RSV vaccine (Abrysvo) to protect their babies.
- The Abrysvo vaccine helps a pregnant person make protective proteins (antibodies) to pass to their baby. The vaccine can reduce a baby’s risk of being hospitalized from RSV by 57% in the first six months after birth.
Infants and young children
- All infants younger than eight months of age should receive a single dose of nirsevimab, a monoclonal antibody immunization, shortly before or during their first RSV season.
- Nirsevimab contains monoclonal antibodies, which are man-made proteins that mimic the immune system’s ability to fight off harmful pathogens, such as viruses. Nirsevimab reduces the risk of severe RSV disease by 80%.
- Most children whose parent received the RSV vaccine while pregnant do not need a dose of nirsevimab too. Please consult the child’s healthcare provider for more detail about who might be eligible for both products.
- Some children ages eight through 19 months who are at increased risk for severe RSV disease and entering their second RSV season may be eligible. Please consult the child’s healthcare provider about this use.
- Currently, there is no RSV vaccine that is indicated for infants and toddlers.

History of RSV immunization products:

In 2023, the U.S. Food and Drug Administration (FDA) approved two new RSV vaccines. They are Arexvy (manufactured by GSK), and Abrysvo (Pfizer). In 2024, FDA approved a third RSV vaccine mRESVIA (Moderna). Less information is available about mRESVIA at this time.
While each vaccine is indicated to prevent RSV-related severe lower respiratory tract disease in older adults, it should be noted that some vaccines have additional indications. Depending on the indication for vaccination, these products may not be interchangeable.
In 2023, the monoclonal antibody nirsevimab (brand name Beyfortus, Sanofi) was approved by FDA

How can I learn more about Respiratory Syncytial Virus?

If you have individual patient concerns or questions about RSV, please contact your or your child’s healthcare provider.
For general questions about RSV, contact your local health department. A directory of local health departments is located at http://www.vdh.virginia.gov/local-health-districts/.
More RSV information is available on the CDC website at cdc.gov/rsv/.

July 2024