Respiratory syncytial virus (RSV) causes infections of the lungs and respiratory tract. It's so common that most children have been infected with the virus by age 2. Respiratory syncytial (sin-SISH-ul) virus can also infect adults.
In adults and older, healthy children, RSV symptoms are mild and typically mimic the common cold. Self-care measures are usually all that's needed to relieve any discomfort.
RSV can cause severe infection in some people, including babies 12 months and younger (infants), especially premature infants, older adults, people with heart and lung disease, or anyone with a weak immune system (immunocompromised).
Signs and symptoms of respiratory syncytial virus infection most commonly appear about four to six days after exposure to the virus. In adults and older children, RSV usually causes mild cold-like signs and symptoms. These may include:
RSV infection can spread to the lower respiratory tract, causing pneumonia or bronchiolitis — inflammation of the small airway passages entering the lungs. Signs and symptoms may include:
Infants are most severely affected by RSV. Signs and symptoms of severe RSV infection in infants include:
Most children and adults recover in one to two weeks, although some might have repeated wheezing. Severe or life-threatening infection requiring a hospital stay may occur in premature infants or in anyone who has chronic heart or lung problems.
Because RSV and coronavirus disease 2019 (COVID-19) are both types of respiratory viruses, some symptoms of RSV and COVID-19 can be similar. In children, COVID-19 often results in mild symptoms such as fever, runny nose and cough. For adults with COVID-19, symptoms may be more severe and may include trouble breathing.
Having RSV may lower immunity and increase the risk of getting COVID-19 — for kids and adults. And these infections may occur together, which can worsen the severity of COVID-19 illness.
If you have symptoms of a respiratory illness, your doctor may recommend testing for COVID-19.
Seek immediate medical attention if your child — or anyone at risk of severe RSV infection — has difficulty breathing, a high fever, or a blue color to the skin, particularly on the lips and in the nail beds.
Respiratory syncytial virus enters the body through the eyes, nose or mouth. It spreads easily through the air on infected respiratory droplets. You or your child can become infected if someone with RSV coughs or sneezes near you. The virus also passes to others through direct contact, such as shaking hands.
The virus can live for hours on hard objects such as countertops, crib rails and toys. Touch your mouth, nose or eyes after touching a contaminated object and you're likely to pick up the virus.
An infected person is most contagious during the first week or so after infection. But in infants and those with weakened immunity, the virus may continue to spread even after symptoms go away, for up to four weeks.
By age 2, most children will have been infected with respiratory syncytial virus, but they can get infected by RSV more than once. Children who attend child care centers or who have siblings who attend school are at a higher risk of exposure and reinfection. RSV season — when outbreaks tend to occur — is the fall to the end of spring.
People at increased risk of severe or sometimes life-threatening RSV infections include:
Complications of respiratory syncytial virus include:
Respiratory syncytial virus can infect anyone. But premature babies and young infants, as well as older adults, with heart or lung disease or a weakened immune system are at higher risk of severe infection.
Two main options exist to help prevent young infants from getting severe RSV. One is an antibody product given to the infant. The other is an RSV vaccine for pregnant people to help protect their baby from birth through 6 months of age. Both are approved by the U.S. Food and Drug Administration (FDA). You and your healthcare professional can discuss which option is best to protect your child.
Antibody product called nirsevimab (Beyfortus). This antibody product is a single-dose shot given in the month before or during RSV season. It's for babies younger than 8 months born during or entering their first RSV season. Nirsevimab also can be given to children 8 months through 19 months old who are at higher risk of severe RSV disease through their second RSV season. In the U.S., the RSV season typically is November through March, but it varies in Florida, Alaska, Hawaii, Puerto Rico, Guam and other U.S. Pacific island territories.
In rare situations, when nirsevimab is not available or a child is not eligible for it, another antibody product called palivizumab may be given. But palivizumab requires monthly shots given during the RSV season, while nirsevimab is only one shot. Palivizumab is not recommended for healthy children or adults.
Older adults have weaker immune systems, especially those with ongoing conditions, such as heart or lung disease. To help prevent RSV infection, the FDA approved RSV vaccines for adults age 60 and older.
The CDC recommends that adults age 60 and older talk with their healthcare professional about getting an RSV vaccine, especially if they're at higher risk of getting severe RSV. Two vaccines are available for this age group: Abrysvo and Arexvy. The CDC does not recommend one over the other. Each is a single-dose shot.
Talk with your healthcare team about the benefits and risks of RSV vaccines for your situation.
These lifestyle habits can help prevent the spread of this infection:
Your doctor may suspect respiratory syncytial virus based on the findings of a physical exam and the time of year the symptoms occur. During the exam, the doctor will listen to the lungs with a stethoscope to check for wheezing or other abnormal sounds.
Laboratory and imaging tests aren't usually needed. However, they can help diagnose RSV complications or rule out other conditions that may cause similar symptoms. Tests may include:
Treatment for respiratory syncytial virus generally involves self-care measures to make your child more comfortable (supportive care). But hospital care may be needed if severe symptoms occur.
Your doctor may recommend an over-the-counter medication such as acetaminophen (Tylenol, others) to reduce fever. (Never give aspirin to a child.) Use of nasal saline drops and suctioning may help clear a stuffy nose. Your doctor may prescribe antibiotics if there's a bacterial complication, such as bacterial pneumonia.
Keep your child as comfortable as possible. Offer plenty of fluids and watch for signs of loss of body fluids (dehydration), such as dry mouth, little to no urine output, sunken eyes, and extreme fussiness or sleepiness.
If the RSV infection is severe, a hospital stay may be necessary. Treatments at the hospital may include:
An inhaler (bronchodilator) or steroids are not proved to be helpful in treating RSV infection.
You may not be able to shorten the length of a respiratory syncytial virus infection, but you can try to relieve some signs and symptoms.
If your child has RSV, do your best to comfort or distract him or her — cuddle, read a book or play a quiet game. Other tips for relieving symptoms are:
Unless severe symptoms result in an emergency room (ER) visit, you're likely to start by seeing your family doctor or your child's doctor. Here's some information to help you get ready for your appointment, and know what to expect from your doctor.
Before your appointment, you may want to make a list of:
Questions to ask your doctor may include:
Don't hesitate to ask any additional questions you may think of during your appointment.
Your doctor is likely to ask you a number of questions, such as:
Your doctor will ask additional questions based on your responses, symptoms and needs. Preparing and anticipating questions will help you make the most of your time with the doctor.