Health Topic

Respiratory Syncytial Virus Infections

Respiratory syncytial virus (RSV) causes cold-like symptoms in adults and healthy children but can cause serious problems in babies. Read more.

Reviewed Reviewed by a registered pharmacistGeneral information

Also called: RSV

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About Respiratory Syncytial Virus Infections

Respiratory syncytial virus, or RSV, is a common respiratory virus. It usually causes mild, cold-like symptoms. But it can cause serious lung infections, especially in infants, older adults, and people with serious medical problems.

RSV spreads from person to person through:

  • The air by coughing and sneezing
  • Direct contact, such as kissing the face of a child who has RSV
  • Touching an object or surface with the virus on it, then touching your mouth, nose, or eyes before washing your hands

People who have an RSV infection are usually contagious for 3 to 8 days. But sometimes infants and people with weakened immune systems can continue to spread the virus for as long as 4 weeks.

RSV can affect people of all ages. But it is very common in small children; nearly all children become infected with RSV by age 2. In the United States, RSV infections usually occur during RSV season, which is usually fall through spring.

Certain people are at higher risk of having a severe RSV infection:

  • Infants
  • Older adults, especially those ages 65 and older
  • People with chronic medical conditions such as heart or lung disease
  • People with weakened immune systems

The symptoms of RSV infection usually start about 4 to 6 days after infection. They include:

  • Runny nose
  • Decrease in appetite
  • Cough
  • Sneezing
  • Fever
  • Wheezing

These symptoms usually appear in stages instead of all at once. In very young infants, the only symptoms may be irritability, decreased activity, and trouble breathing.

RSV can also cause more severe infections, especially in people at high risk. These infections include bronchiolitis, an inflammation of the small airways in the lung, and pneumonia, an infection of the lungs.

Your health care provider may use many tools to make a diagnosis:

  • A medical history, including asking about symptoms.
  • A physical exam.
  • A lab test of nasal fluid or another respiratory specimen to check for RSV. This is usually done for people with severe infection.
  • Tests to check for complications in people with severe infection. The tests may include a chest x-ray and blood and urine tests.

There is no specific treatment for RSV infection. Most infections go away on their own in a week or two. Over-the-counter pain relievers can help with the fever and pain. However, do not give aspirin to children. And do not give cough medicine to children under four. It is also important to get enough fluids to prevent dehydration.

Some people with severe infection may need to be hospitalized. There, they might get oxygen, a breathing tube, or a ventilator.

There are some vaccines to protect against RSV illness. Two of them are for people ages 60 and older. If you are in this age group, talk to your provider about whether an RSV vaccine would be right for you.

If you are pregnant, there is a vaccine that is available to give between 32 and 36 weeks of pregnancy. It helps protect their newborn babies from RSV illness for the first 6 months of life.

There are two medicines to help prevent severe RSV illness in babies and young children. These medicines may help prevent severe RSV illness, but they can't cure or treat children who already have RSV. And they cannot prevent an RSV infection. Both medicines are given by injections (shots).

One medicine is given to infants who are younger than 8 months during their first RSV season. This includes infants who are born during RSV season. This medicine may also be given to some children between the ages of 8 and 19 months who are at high risk for severe RSV illness. For example, they might be at high risk because they:

  • Were born prematurely
  • Have congenital heart disease
  • Have chronic lung disease
  • Have a weakened immune system

The other medicine is given monthly during RSV season. It is for children under 24 months of age who are at high risk for severe RSV illness.

There are also some steps you can take to lower your risk of getting or spreading an RSV infection, including:

  • Washing your hands often with soap and water for at least 20 seconds
  • Avoiding touching your face, nose, or mouth with unwashed hands
  • Avoiding close contact, such as kissing, shaking hands, and sharing cups and eating utensils, with others if you are sick or they are sick
  • Cleaning and disinfecting surfaces that you frequently touch
  • Covering coughs and sneezes with a tissue. Then throw away the tissue and wash your hands
  • Staying home when sick

Centers for Disease Control and Prevention

It sits within Children and Teenagers, Infections and Lungs and Breathing.

The lead U.S. institute for this subject is the National Institute of Allergy and Infectious Diseases.

When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.

Research on Respiratory Syncytial Virus Infections

549 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

Start Here

Symptoms

Diagnosis and Tests

Prevention and Risk Factors

Clinical Trials

Patient Handouts

Medical subject headings

Clinicians and researchers index this subject under Respiratory Syncytial Virus Infections. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for Respiratory Syncytial Virus Infections, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.