Respiratory Syncytial Virus

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Respiratory Syncytial Virus (RSV) Overview

What is RSV?

RSV is a common respiratory virus that causes mild, cold-like symptoms. Most people recover in a week or two, but RSV can be serious, especially in infants and older adults. RSV infection is the leading cause of hospitalization in U.S. infants.

You can get RSV by:

  • Having the virus touch your eyes, nose, or mouth when an infected person coughs or sneezes.
  • Having direct contact with the virus, like kissing an infected child.
  • Touching a surface that has the virus on it, like a doorknob, and then touching your face.

People with RSV are contagious for 3 to 8 days. They can spread RSV a day or more before they show signs of illness. Infants and those with weak immune systems can spread the virus for as long as 4 weeks.

New treatments have been developed to reduce the risk of severe RSV. The vaccine section of this page highlights these treatments.

Read more about RSV and how it affects people on the Centers for Disease Control and Prevention (CDC) website.

What are the symptoms of RSV?

People show symptoms about 4 to 6 days after getting exposed to a sick person. Symptoms usually include:

  • Runny nose
  • Less appetite
  • Coughing
  • Sneezing
  • Fever
  • Wheezing

However, some adults can get an RSV infection and not have any symptoms.

Very young babies may only have the following symptoms:

  • Irritability
  • Decreased activity
  • Eating or drinking less
  • Difficulty breathing

Who is at risk?

People at most risk for serious illness include:

  • Premature infants
  • Young children with certain medical conditions or weak immune systems
  • Adults with weak immune systems
  • Older adults, especially those with heart or lung disease

Babies, young children, and older adults are most likely to be hospitalized or have severe symptoms from RSV.

Children under 1 year of age are most likely to experience infection or inflammation of the lungs, or pneumonia.

Older adults may experience trouble breathing or dehydration.

Limit the spread of RSV

RSV season usually starts in the fall and peaks in the winter. Like other respiratory viruses, you can help to limit the spread of RSV in these ways:

  • Wash your hands often with soap and water for at least 20 seconds.
  • Avoid touching your eyes, nose, and mouth with unwashed hands.
  • Cover your coughs and sneezes with a tissue or your upper shirt sleeve.
  • Avoid close contact with sick people.
  • Clean and disinfect surfaces that people touch frequently.
  • Stay home when you’re sick.

How to care for RSV?

Antiviral medication is not routinely recommended to treat RSV. Most RSV infections go away on their own in a week or two. However, RSV can cause severe illness in some people. Infants, young children, and older adults are at increased risk of severe RSV. Some people with RSV infection, especially infants younger than 6 months of age and older adults, may need to be hospitalized if they are having trouble breathing or are dehydrated. More information about severe RSV can be found on the CDC’s website.

Take steps to relieve mild symptoms:

  • Manage fever and pain with over-the-counter fever reducers and pain relievers, such as acetaminophen or ibuprofen. Never give aspirin to children.
  • Drink enough fluids. It is important for people with RSV infection to drink enough fluids to prevent dehydration (loss of body fluids).
  • Talk to your health care provider before giving your child nonprescription cold medicines. Some medicines contain ingredients that are not good for children.

More information about RSV including prevention and diagnosis can be found on the CDC website.

RSV Monoclonal Antibody Products for Infants and Young Children

Monoclonal antibody products

Monoclonal antibody products provide antibodies against RSV disease and are given by injection. These antibodies provide protection during RSV season. Monoclonal antibody products should not be used to treat children already infected with RSV. There are two products currently available.

Nirsevimab (Beyfortus) is a long-lasting monoclonal antibody product to keep babies and young children from developing severe RSV disease. Protection from nirsevimab lasts at least five months.

Palivizumab (Synagis) is another monoclonal antibody product, but it is only for children less than 2 years of age with certain conditions that make them at more risk for severe disease. This treatment is given once a month during RSV season.

When do children get nirsevimab?

Nirsevimab is recommended for all children younger than 8 months during the first RSV season that they may have contact with the virus. Children between 8 and 19 months of age who are at higher risk due to medical conditions or weak immune systems can get nirsevimab the second RSV season.

Children between 8 and 19 months of age who are American Indian and Alaska Native are also recommended to get nirsevimab in their second RSV season since they are at more risk of getting severe RSV disease.

What are the side effects of nirsevimab?

The most common side effects of nirsevimab include:

  • Rash.
  • Puffiness or swelling of the eyelids, face, lips, or tongue.

Why is nirsevimab important?

RSV infection is the leading cause of hospitalization in U.S. infants. Nearly all children are infected with RSV by 2 years of age.

Each year, RSV causes 50,000 to 80,000 hospitalizations and 100 to 300 deaths in children younger than 5. Premature infants have higher rates of hospitalization from RSV.

In trials, nirsevimab was effective at reducing lower respiratory tract infections from RSV that require hospitalization, and intensive care unit (ICU) admission.

Nirsevimab is expected to lower the cost of RSV treatment in children by replacing a more costly monoclonal antibody treatment.

Where do children get nirsevimab?

Nirsevimab will be available in health care provider offices in early October 2023.

Respiratory Syncytial Virus (RSV) Vaccine for Pregnant People

Abrysvo, Pfizer’s RSV vaccine, is recommended for use during pregnancy. RSV vaccination during pregnancy provides families with another option to protect babies from getting very sick from RSV.

When do pregnant people get RSV vaccine?

Pregnant people should get one dose of RSV vaccine from 32 weeks through 36 weeks of pregnancy to protect their babies. The vaccine is recommended for pregnant people during RSV season, which is usually from September through January in the United States.

Infants should not get nirsevimab if their parent was vaccinated for RSV at least 2 weeks before delivery. It takes about 2 weeks for protection against RSV disease. Some infants may still need to get nirsevimab even if the parent received RSV vaccine, so it’s best to check with the doctor or nurse.

What are the side effects of RSV vaccine during pregnancy?

The most common side effects of RSV vaccines include:

  • Pain at the injection site
  • Headache
  • Muscle pain
  • Nausea

Expecting parents should discuss with their doctor if they should get RSV vaccine during pregnancy or provide their newborn with nirsevimab, an RSV antibody product.

Respiratory Syncytial Virus (RSV) Vaccine for Older Adults

RSV vaccines

Arexvy and Abrysvo are two RSV vaccines approved in the United States. These vaccines are currently recommended for adults 60 years and older. The vaccines work by causing an immune response that actively protects people if they are exposed to RSV.

When do older adults get RSV vaccine?

Adults may receive one dose of RSV vaccine after discussing with their health care provider if the vaccine will be beneficial. People who are 60 or older and have weak immune systems, chronic medical conditions, or live in nursing homes or other medical facilities are at higher risk for severe RSV illness. Those at higher risk may benefit from RSV vaccination.

What are the side effects of RSV vaccine?

The most common side effects of RSV vaccines include:

  • Pain at the injection site
  • Redness
  • Fatigue
  • Muscle pain
  • Headache

Why is RSV vaccine important?

RSV infection can be serious, especially in older adults. RSV can sometimes lead to worsening of other medical conditions, such as asthma, chronic obstructive pulmonary disease (COPD), and congestive heart failure.

RSV vaccines can help prevent serious illness and can prevent lung infections, like pneumonia.

Where can I get the RSV vaccine?

Most pharmacies in your local area offer RSV vaccine. You can also talk with your primary care provider or local health department.

Resources

Vaccine information statement and resources

The Vaccine Information Statement (VIS) is given to people at the time of vaccination. It explains the benefits and risks of the specific vaccination.

Read the current RSV Vaccine VIS from the Centers of Disease Control and Prevention (CDC)

Additional resources for the public

Additional resources for health care providers