RSV Transmission: How Contagious Is Respiratory Syncytial Virus?

Medically Reviewed By Michaela Murphy, PA-C
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RSV, or respiratory syncytial virus, is a common and highly contagious respiratory infection. It’s usually mild, but it can become serious in infants and some people with chronic conditions. Find out how RSV is spread, how long a person can transmit the virus, and what you can do to prevent it.

What is RSV, and how contagious is it?

Mother and child washing hands
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RSV, or respiratory syncytial virus, is a viral infection that primarily affects the airways, including the nose, throat, and lungs. RSV spreads very easily, particularly when someone has symptoms. It can also spread before symptoms develop and after symptoms subside. RSV infections are most common in the colder months, but that can vary by region.

Most people get a cough, stuffy nose, and perhaps a low fever and fatigue. RSV can become severe in young babies, older adults, and some people with chronic health concerns or weak immune systems. Severe cases can cause breathing difficulties and become life threatening.

Even if you have contracted RSV, as most people have by the time they are 2 years old, you don’t develop immunity, so you become ill whenever you are exposed to the virus during your lifetime. However, subsequent infections tend to be less severe.

How does RSV spread?

RSV can spread through droplets in the air expelled during a cough or sneeze. It’s even more likely to be spread through touching surfaces with the virus and then touching the face, particularly the eyes and nose.

RSV can live on a hard surface for 12 hours and on your hands and soft surfaces for more than half an hour. It’s common for children to get infected at a child care center or school and then pass it on to other family members.

What are the stages of RSV?

People with RSV can begin to show symptoms 4–6 days after acquiring the virus. The illness usually develops in phases.

Initially, it’s usually a mild, cold-like disease. If it worsens, it moves into the lungs and can cause coughing and wheezing. In severe cases, it progresses to the point that it can cause breathing difficulties.

Some people may need to be hospitalized so they can get supplemental oxygen. In the most serious cases, a person may need to be on a ventilator, a mechanical breathing machine. A hospital stay lasts until symptoms improve, usually within a few days.

How long is a person with RSV contagious?

Generally, the contagious period for RSV is 3–8 days. However, in some people, the virus can be spread for up to 4 weeks, even after a person no longer has symptoms. This is especially true for seniors, infants, and those with weakened immune systems because it can take longer for their bodies to clear the virus.

How can you prevent the spread of RSV?

You can help prevent the spread of this highly contagious virus in the same way you can protect against other viruses. If you have symptoms or reason to believe you have been exposed to RSV:

  • Wash your hands often with soap and water for at least 20 seconds.
  • Cover your nose and mouth with a tissue when you cough or sneeze.
  • Wipe down surfaces like doorknobs, light switches, counters, and shared electronic devices.
  • Avoid touching your face or rubbing your eyes.
  • Stay away from those at high risk, including children younger than 2, people over 65, and anyone with a weakened immune system or chronic heart and lung disease.
  • If you have symptoms, avoid close contact with other people and do not share eating utensils or grooming tools.

Practicing social distancing and masking may also help prevent the spread of RSV. Distancing and masking likely contributed to the decrease in RSV rates during the 2020-2021 season, when these interventions were used for COVID-19.

A medication called palivizumab (Synagis), a monoclonal antibody, can help prevent severe cases of RSV. Monoclonal antibodies are manufactured proteins that produce antibodies that fight disease.

The American Association of Pediatrics has said it supports the use of palivizumab in high risk infants when RSV infection rates are like those of a typical fall and winter season when the virus is most commonly transmitted.

Talk with your pediatrician if you think your baby might be at high risk. Vaccines for RSV are in the late stages of clinical testing and may be approved soon. Vaccines will prevent the spread of RSV and undergo rigorous safety testing.


RSV, or respiratory syncytial virus, is a very contagious and common infection. In most people with the virus, it causes mild, cold-like illness. Still, in infants under 6 months, older people, and people with weakened immune systems or chronic diseases, it can become severe and even be life threatening.

You can help contain the spread of RSV by frequent and thorough handwashing, keeping often-used surfaces clean, covering your nose and mouth if you sneeze, and staying away from children and others with the virus or whom you may transmit the virus.

There is a treatment for severe RSV, and a vaccine may be on the horizon, but in the meantime, prevention is important.

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Medical Reviewer: Michaela Murphy, PA-C
Last Review Date: 2022 Oct 27
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