What is RSV?

Editor’s Note: post last updated August 3, 2023. 

You probably know someone who has gotten sick with RSV (Respiratory Syncytial Virus) given the number of cases in the U.S. this fall and winter season. While the recent RSV surge has made headlines, this common respiratory virus has been a threat to infants and young children, older adults, and adults with chronic medical conditions for years.

Learn more about the virus, its symptoms, and how to best protect your family from RSV.

What is RSV?

RSV is a common respiratory virus that usually spreads seasonally. In infants and young children, RSV is very common – in fact, it is the most common cause of acute lower respiratory infection in young children. Almost all children will get an RSV infection by the time they are 2 years old. RSV can be very serious for some babies and young children, especially premature infants, infants younger than 6 months, and young children with pre-existing health conditions. In one analysis that looked at available data through 2019, researchers found that (globally) one in every 28 deaths in children between 1 month and 6 months old is attributable to RSV. Here in the U.S., RSV is the leading cause of hospitalization in children younger than one year old. Approximately 75% of infants hospitalized for RSV are not born prematurely and don’t have underlying medical conditions.  

In older adults – especially those age 65 years and older – RSV causes upwards of 120,000 hospitalizations and 10,000 deaths every year 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. Learn more about older adults at the highest risk for RSV here.   

People of any age can be infected with RSV. In healthy adults, RSV often looks like a common cold. – but RSV can be transmitted to others just like flu, COVID, or other infectious diseases. It can spread through respiratory droplets when an infected person coughs or sneezes, as well as through contact with contaminated surfaces. 

RSV disproportionately affects infants & children of color. Learn more about the health disparities impacting infants with RSV from Dr. Whitley-Williams:

How do I know if I or my child has RSV?

Common symptoms of RSV include:  

• Fever  
• Runny or stuffy nose  
• Cough  
• Shortness of breath  
• Wheezing  

If someone is sick and having difficulty breathing, 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). 

Why are there so many cases of RSV this season?

Prevention measures that we used during the COVID pandemic, like wearing a mask, staying home, and keeping six feet apart, worked well to reduce the spread of many other viruses . But with the relaxation of these precautions, viruses have come back in full force.  

In the U.S., RSV typically circulates during the fall and winter months. This season, RSV has hit the U.S. hard, circulating with flu and COVID-19 and causing what some medical experts have referred to as a “tripledemic.” As a result, many children’s hospitals have been overwhelmed.  

Can RSV be prevented?

The first-ever vaccines to protect against respiratory syncytial virus (RSV) are now available for older adults. The CDC & its independent Advisory Committee on Immunization Practices (ACIP) have recommended new RSV vaccines for adults ages 60 and up – one of the groups most at risk for serious illness from RSV infection. Adults 60+ may get an RSV vaccine based on a conversation with their health care provider about their health risk factors.

A new prevention tool for babies will also be available soon. At an August 3 meeting, a monoclonal antibody called nirsevimab was recommended by CDC experts for use in infants in their first RSV season and in high-risk  young children during their second RSV season. Monoclonal antibodies are antibodies administered through an external source which allow you to fight off infections for a certain period of time (a process called “passive immunity”). Monoclonal antibodies do not teach your body to make its own antibodies. Nirsevimab can provide strong protection in infants and young children for at least a year.  

The vaccines and monoclonal antibodies have been tested in clinical trials and data has been carefully reviewed by independent experts on ACIP to ensure that they’re safe and effective and that the benefits outweigh any potential risks. Like all recommended vaccines, safety monitoring will continue after they are widely available for use. 

Other vaccines against RSV are also under review by the FDA – one of which is being studied for use in pregnant people to provide protection to babies, with positive results so far.  

While we wait for vaccines and mAbs to be widely available, you can take steps to protect yourself, your family, and your community. You can stop the spread of RSV by wearing masks, keeping your distance from people who are sick, washing your hands often, and disinfecting surfaces regularly.

Bookmark this page as we will update it as treatments and vaccines become available!