What is respiratory syncytial virus (RSV)? Symptoms, causes and care

This article is up to date as of October 28, 2025, and based on vaccine guidance provided by the U.S. Centers for Disease Control and Prevention (CDC). Individual states may adopt their own vaccine policies and recommendations based on local public health assessments and regulatory frameworks. For the most up-to-date information, consult your state or local health department or your health care provider.

When winter rolls around, it can sometimes bring with it coughing, sneezing and wheezing that comes with seasonal illnesses. This may be caused by respiratory syncytial virus (RSV), which is a highly contagious virus that causes cold-like symptoms. However, there are vaccinations available for some people that can help them protect themselves from infections caused by RSV.

In this article:

What is RSV?

Respiratory syncytial virus (RSV) is an infection that affects the lungs and airways. For most people, symptoms of RSV are mild and go away in about a week or two. But for vulnerable individuals, RSV can lead to serious illness or death.

In the U.S., RSV generally arises in the fall, usually peaking in December through January. Every year, it is responsible for about 110,000 to 180,000 hospitalizations of those age 50 and older and about 58,000 to 80,000 hospitalizations for children younger than age 5.

The infection is highly contagious; among vulnerable groups, it can lead to lower respiratory tract diseases (LRTD) like pneumonia. It can also worsen conditions like asthma, chronic obstructive pulmonary disease and congestive heart failure. In babies and young children whose immune systems aren’t fully formed, it can lead to respiratory problems and the need for breathing support methods.

RSV is the most common cause of bronchiolitis and pneumonia in children under age 1. It is so common in children that “the majority of children will have been infected with RSV by the age of 2,” says Krupa Playforth, MD, a board-certified pediatrician at Warm Heart Pediatrics and an American Academy of Pediatrics fellow.

Symptoms of RSV

Symptoms of RSV are similar to those of the common cold and may include:

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

Symptoms usually become apparent four to six days after infection and typically appear in stages rather than all at once. These symptoms generally last two to eight days, but they can linger up to two weeks, adds Dr. Playforth.

In very young infants, symptoms may be decreased activity, irritability and difficulty breathing. “Difficulty breathing often interferes with their ability to feed, so people may notice that, too, as well as dehydration,” Dr. Playforth says.

RSV causes and transmission

RSV is a virus that is very contagious. It can spread when an infected person coughs or sneezes and those virus droplets get in a person’s eyes, nose or mouth. People can also get it if they touch a surface that has RSV on it and then touch their face without washing their hands first, or if they have direct contact with the virus, such as kissing the face of someone with RSV.

Children who attend child care centers or have siblings who attend school or day care are also at a higher risk of RSV exposure.

How long is RSV contagious?

People infected with RSV are usually contagious for three to eight days. Some infants and people with weakened immune systems can spread RSV even after they stop showing symptoms.

Furthermore, people can get RSV multiple times over their lifetime because the immune system doesn’t form lasting immunity to the infection.

How is RSV diagnosed?

Though not required for mild cases of RSV, health care professionals can perform RSV testing. “There are antigen tests and molecular (or polymerase chain reaction [PCR]) tests, which can be done via nasal swab,” says Dr. Playforth.

For severe cases that lead to hospitalization, additional methods — such as computed tomography (CT) scans or chest X-rays — may be used.

How to manage RSV?

Most mild RSV infections resolve on their own in a week or two, so antiviral medication is not typically recommended to treat the infection. “Antibiotics cannot be used to treat it, so we focus on supporting the body with fluids, pain management and rest,” says Dr. Playforth.

The best ways to help relieve symptoms include:

• Drink plenty of fluids to prevent dehydration.
• Ease cough and congestion with over-the-counter (OTC) cough, cold and flu symptom relief support medicines.
• Manage pain and fever with OTC pain relief support products like acetaminophen or ibuprofen.

Be sure to talk to a health care provider before caring for a child at home and before giving them any sort of medicine. Always consult a pharmacist or health care provider before taking any OTC medications.

Who should get an RSV vaccine?

Vaccines are available to help prevent severe RSV in vulnerable individuals.

For people over age 75 or those ages 50 through 74 with an increased risk of severe RSV, there are three RSV vaccines available in the U.S. It is recommended that these age groups get a single dose of an RSV vaccine after talking to their health care provider to determine if they would benefit from such an intervention. This vaccine is not currently offered annually.

Pregnant people are also eligible to receive a specific formulation during weeks 32 to 36 of their pregnancy to help protect their newborns from severe RSV illness. These can be given September through January.

For babies and young children, there are two available monoclonal antibody products: nirsevimab and clesrovimab. Though not vaccines, these antibodies can serve as an added barrier of defense against severe RSV infections. Nirsevimab is recommended for infants younger than 8 months, who were born during or are entering their first RSV season and the parent didn’t receive the RSV vaccine during pregnancy, or who were born within 14 days of vaccination. Some infants and children between 8 and 19 months who are at increased risk for severe RSV disease are eligible to receive nirsevimab shortly before the start of their second RSV season.

In past years, the antibody palivizumab was recommended for children. As of December 31, 2025, Palivizumab will no longer be available.

Risk factors and complications of RSV

Adults at increased risk for severe RSV include:

• People age 75 and older
• People with chronic heart or lung disease
• People with weakened immune systems
• People with underlying medical conditions
• People living in nursing homes

Children at increased risk of developing severe RSV include:

• Children who are American Indian or Alaska Native
• Children born prematurely
• Children with chronic lung disease at birth or congenital heart disease
• Children with weakened immune systems
• Children with severe cystic fibrosis
• Children who have neuromuscular disorders
• Infants and young children (the younger the age, the higher the risk)

Someone who falls into these categories or has children who do should talk with a health care provider about RSV protection and management.

“As with many other respiratory conditions, anyone can have a severe case,” says Dr. Playforth. “The most important thing to remember is to trust your gut as a parent. If a child seems like they are doing poorly, it is extremely important to have them evaluated by a health care provider right away.”

If illness strikes or worsens or the risk for contracting severe RSV is high, talk to a health care provider today.