Respiratory syncytial (sin-SISH-uhl) virus, or RSV, is a common respiratory virus that usually causes mild, cold-like symptoms. Most people recover in a week or two, but RSV can be serious. Infants and older adults are more likely to develop severe RSV and need hospitalization. Vaccines are available to protect older adults from severe RSV. Monoclonal antibody products are available to protect infants and young children from severe RSV.

RSV in Infants and Young Children

RSV can be dangerous for some infants and young children. Monoclonal antibody products can help protect babies and young children from severe RSV disease

RSV in Older Adults and Adults with Chronic Medical Conditions

RSV infections can be dangerous for older adults. RSV vaccine can help protect adults ages 60 and older from RSV.

Respiratory syncytial virus (RSV) is a contagious virus that affects the lungs and breathing passages. Most children get RSV infection by age 2, but you can get infected at any age and more than once in your life. The symptoms are usually similar to the common cold. Most people recover in a week or two, but others at high risk may get very sick and develop pneumonia or bronchiolitis (inflammation of the small airways in the lungs). There is no vaccine, but scientists are working to develop one. Until then, there are ways you can help prevent RSV infection.

Key Facts

• RSV usually causes mild, cold-like symptoms such as runny nose, decrease in appetite, coughing, sneezing, fever, and wheezing.
• Infants and older adults may develop severe infections from RSV, such as pneumonia or bronchiolitis.
• Most kids get an RSV infection by age 2. However, you can get an RSV infection at any age and more than once in your life.
• RSV spreads when an infected person coughs or sneezes, or shares cups and eating utensils with others.
• You can help protect yourself and others from RSV infections by washing your hands often with soap and water for at least 20 seconds.

RSV Can Be Serious

For most people, RSV infections are mild and clear on their own. But some people develop severe infections, such as pneumonia and bronchiolitis. People at high risk include very young infants, premature babies, young children with chronic lung or heart disease, older adults, and people with weakened immune systems.

Wash Your Hands Often

Wash your hands often with soap and water for 20 seconds, and help young children do the same. Proper hand hygiene can help protect you from getting RSV infection as well as prevent the spread of infection to others when you are sick.

Cover Your Cough and Sneeze

RSV can spread when an infected person coughs or sneezes. To help prevent germs from spreading, cover your coughs and sneezes with a tissue or your upper shirt sleeve, not your bare hands. Throw the tissue in the trash and wash your hands.

Avoid Sharing When Sick

You can get RSV infection if you share cups or eating utensils with others. You can also get infected if you touch surfaces, such as toys or doorknobs, that have the virus on them, then touch your eyes, nose or mouth.

Prevention Tips

• Wash your hands often with soap and water for at least 20 seconds, and help young children do the same.
• Cover your coughs and sneezes with a tissue or your upper shirt sleeve, not your bare hands. Throw the tissue in the trash and wash your hands.
• Avoid touching your eyes, nose, and mouth with unwashed hands.
• Avoid close contact, such as kissing, or sharing cups or eating utensils, with sick people.
• Clean and disinfect frequently touched surfaces, such as toys and doorknobs.

Respiratory Syncytial Virus (RSV) is a viral infection of the respiratory (breathing) tract. Almost all children will get RSV at least once by the time they are 2. It's the most common cause of respiratory infections in this age group but may cause severe illness in children under 1. While there is no vaccine for RSV, there are many ways to limit the spread.

As with any illness, notify families with any concerns about a child's health and contact 911 or your local emergency system if you think a child may be having a medical emergency.

Symptoms

Most people with RSV have mild symptoms lasting five to seven days. RSV causes cold symptoms in the upper respiratory tract, which includes the nose, mouth, and throat. Sometimes, it can lead to breathing problems in the small airways (bronchiolitis) or lungs (pneumonia) of the lower respiratory tract. These serious breathing problems may require hospitalization. Young children becoming more severely ill may feed poorly, have fewer wet diapers, be less active, or be more difficult to soothe — with or without worsening respiratory symptoms. Children with any symptoms of more severe illness should see a health care provider.

RSV Symptoms in Young Children

For more information about RSV and a video showing symptoms of respiratory distress, see RSV: When It's More Than Just a Cold, from the American Academy of Pediatrics.

How It Spreads

RSV spreads very easily from person to person through:

• Droplets in the air from a cough or sneeze
• Direct contact with nose and mouth secretions
• Contact with the virus on hands, surfaces, toys, and other objects and then touching your mouth, nose, or eyes before washing your hands

Young children with the infection can spread the virus before they get symptoms and for days or weeks after getting sick. RSV infections occur throughout the year, but most outbreaks are in winter.

Who Is at Risk

Premature infants and young children with heart or lung disease or weakened immune systems are at highest risk for severe RSV. Severe cases may require hospitalization.

Educators are often exposed to children with RSV and may get infected more than once. Adults who are older, who have chronic heart or lung disease, or who have weakened immune systems are at higher risk for severe RSV.

Diagnosis

Health care providers usually diagnose RSV based on symptoms and a physical exam. They sometimes test for RSV with a nasal swab. RSV symptoms can be like COVID-19 and influenza, so health care providers may test for all three illnesses at the same time.

Limit the Spread

Follow infection control practices to help keep children and adults healthy.

• Stay home when you're sick.
• Do daily health checks as children enter your program for the day.
• Wash hands often with soap and water throughout the day.
• Don't allow children to share mouthed toys, cups, or eating utensils.
• Clean, sanitize, and disinfect surfaces regularly.
• Cover coughs and sneezes.
• Throw away used tissues, and wash hands after using tissues.
• Change clothing soiled with mucous.
• Have fresh air indoors and spend time outdoors.

RSV can spread when

• An infected person coughs or sneezes
• You get virus droplets from a cough or sneeze in your eyes, nose, or mouth
• You have direct contact with the virus, like kissing the face of a child with RSV
• You touch a surface that has the virus on it, like a doorknob, and then touch your face before washing your hands

People infected with RSV are usually contagious for 3 to 8 days and may become contagious a day or two before they start showing signs of illness. However, some infants, and people with weakened immune systems, can continue to spread the virus even after they stop showing symptoms, for as long as 4 weeks. Children are often exposed to and infected with RSV outside the home, such as in school or childcare centers. They can then transmit the virus to other members of the family.

RSV can survive for many hours on hard surfaces such as tables and crib rails. It typically lives on soft surfaces such as tissues and hands for shorter amounts of time.

People are typically infected with RSV for the first time as an infant or toddler and nearly all children are infected before their second birthday. However, repeat infections may occur throughout life, and people of any age can be infected. Infections in healthy children and adults are generally less severe than among infants and older adults with certain medical conditions. People at highest risk for severe disease include

• Premature infants
• Young children with congenital (from birth) heart or chronic lung disease
• Young children with compromised (weakened) immune systems due to a medical condition or medical treatment
• Children with neuromuscular disorders
• Adults with compromised immune systems
• Older adults, especially those with underlying heart or lung disease

In most regions of the United States and other areas with similar climates, RSV season generally starts during fall and peaks in the winter. The timing and severity of RSV season in a given community can vary from year to year.

Most people who get an RSV infection will have mild illness and will recover in a week or two. Some people, however, are more likely to develop severe RSV infection and may need to be hospitalized. Examples of severe infections include bronchiolitis (an inflammation of the small airways in the lung) and pneumonia. RSV can also make chronic health problems worse. For example, people with asthma may experience asthma attacks as a result of RSV infection, and people with congestive heart failure may experience more severe symptoms triggered by RSV. The following groups of people are more likely to get serious complications if they get sick with RSV:

• Infants and Young Children
• Older Adults

RSV can be dangerous for infants and young children. Each year in the United States, an estimated 58,000-80,000 children younger than 5 years are hospitalized due to RSV infection. Children at greatest risk for severe illness from RSV include the following:

• Premature infants
• Infants up to 12 months, especially those 6 months and younger
• Children younger than 2 years with chronic lung disease or congenital (present from birth) heart disease
• Children with weakened immune systems
• Children who have neuromuscular disorders, including those who have difficulty swallowing or clearing mucus secretions

Products to Protect Children from RSV

Two monoclonal antibody products – nirsevimab (Beyfortus) and palivizumab (Synagis) – can help protect babies and young children from severe disease from an RSV infection. Monoclonal antibodies are not vaccines. They provide an extra layer of defense that helps fight RSV infections and protect children from getting very sick. The protection these antibodies provide wanes over time. These products are not treatments for a child who already has RSV infection.

Nirsevimab is recommended for all infants younger than 8 months who are born during – or entering – their first RSV season (typically fall through spring). One dose of nirsevimab can protect infants for 5 months, the length of an average RSV season. A dose of nirsevimab is also recommended for some children between the ages of 8 and 19 months who are at increased risk of severe RSV and who are entering their second RSV season.

Palivizumab is limited to children under 24 months of age with certain conditions that place them at high risk for severe RSV disease. It must be given once a month during RSV season.

If you have any questions about monoclonal antibody products to prevent RSV disease, talk to your child’s doctor. Scientists are gathering and reviewing data on a vaccine intended to be given to pregnant people to protect infants in their first RSV season. Data being reviewed focus on the safety and efficacy of the use of this vaccine in pregnant people to protect their infants.

Severe RSV

Virtually all children get an RSV infection by the time they are 2 years old. Most of the time RSV will cause a mild, cold-like illness, but it can also cause severe illness such as

• Bronchiolitis (inflammation of the small airways in the lung)
• Pneumonia (infection of the lungs)

Some children are at increased risk of severe RSV disease, including those who were born prematurely, or who have chronic lung or heart disease or a weakened immune system.

Two to three out of every 100 infants with RSV infection may need to be hospitalized. Those who are hospitalized may require oxygen, IV fluids (if they aren’t eating and drinking), and mechanical ventilation (a machine to help with breathing). Most improve with this type of supportive care and are discharged in a few days.

Symptoms of RSV

RSV may not be severe when it first starts. However, it can become more severe a few days into the illness. Early symptoms of RSV may include:

• Runny nose
• Eating or drinking less
• Cough, which may progress to wheezing or difficulty breathing

RSV in Very Young Infants

Infants who get an RSV infection almost always show symptoms. This is different from adults, who can sometimes get RSV infections and not have symptoms. In very young infants (less than 6 months old), the symptoms of RSV infection may include:

• Irritability
• Decreased activity
• Eating or drinking less
• Apnea (pauses in breathing for more than 10 seconds)

Fever may not always occur with RSV infections.

Call your healthcare provider if you or your child is having difficulty breathing, not drinking enough fluids, or experiencing worsening symptoms.

Everyday Preventive Measures Can Help Limit the Spread of RSV

RSV season typically starts in the fall and peaks in the winter in most regions of the United States. Like other respiratory viruses, you can help limit the spread of RSV by using the following preventive measures:

• Wash your hands often
  Wash your hands often with soap and water for at least 20 seconds, and help young children do the same. If soap and water are not available, use an alcohol-based hand sanitizer. Washing your hands will help protect you from germs.
• Keep your hands off your face
  Avoid touching your eyes, nose, and mouth with unwashed hands. Germs spread this way.
• Avoid close contact with sick people
  Avoid close contact, such as kissing, and sharing cups or eating utensils with people who have cold-like symptoms.
• Cover your coughs and sneezes
  Cover your mouth and nose with a tissue or your upper shirt sleeve when coughing or sneezing. Throw the tissue in the trash afterward.
• Clean and disinfect surfaces
  Clean and disinfect surfaces and objects that people frequently touch, such as toys, doorknobs, and mobile devices. When people infected with RSV touch surfaces and objects, they can leave behind germs. Also, when they cough or sneeze, droplets containing germs can land on surfaces and objects.
• Stay home when you are sick
  If possible, stay home from work, school, and public areas when you are sick. This will help protect others from catching your illness.

RSV infections can be dangerous for certain adults. Each year, it is estimated that between 60,000-160,000 older adults in the United States are hospitalized and 6,000-10,000 die due to RSV infection. Adults at highest risk for severe RSV infection include:

• Older adults
• Adults with chronic heart or lung disease
• Adults with weakened immune systems
• Adults with certain other underlying medical conditions
• Adults living in nursing homes or long-term care facilities

An RSV vaccine protects against serious disease

RSV vaccine can help protect adults aged 60 years and older from RSV. Talk to your healthcare provider to see if vaccination is right for you.

Severe RSV Infection

When an adult gets RSV infection, they typically have mild cold-like symptoms, but some may develop a lung infection or pneumonia.

RSV can sometimes also lead to worsening of serious conditions such as:

• Asthma
• Chronic obstructive pulmonary disease (COPD) – a chronic disease of the lungs that makes it hard to breathe
• Congestive heart failure – when the heart can’t pump enough blood and oxygen through the body

Older adults who get very sick from RSV may need to be hospitalized. Some may even die. Older adults are at greater risk than young adults for serious complications from RSV because our immune systems weaken when we are older.

What you should do if you or a loved one is at high risk for severe RSV disease

RSV season in most regions of the U.S. starts in the fall and peaks in winter. If you are at high risk for severe RSV infection, or if you interact with an older adult, you should take extra care to keep them healthy:

• Wash your hands often
  Wash your hands often with soap and water for at least 20 seconds. If soap and water are not available, use an alcohol-based hand sanitizer. Washing your hands will help protect you from germs.
• Keep your hands off your face
  Avoid touching your eyes, nose, and mouth with unwashed hands. Germs spread this way.
• Avoid close contact with sick people
  Avoid close contact, such as kissing, and sharing cups or eating utensils with people who have cold-like symptoms.
• Cover your coughs and sneezes
  Cover your mouth and nose with a tissue or your upper shirt sleeve when coughing or sneezing. Throw the tissue in the trash afterward.
• Clean and disinfect surfaces
  Clean and disinfect surfaces and objects that people frequently touch, such as toys, doorknobs, and mobile devices. When people infected with RSV touch surfaces and objects, they can leave behind germs. Also, when they cough or sneeze, droplets containing germs can land on surfaces and objects.
• Stay home when you are sick
  If possible, stay home from work, school, and public areas when you are sick. This will help protect others from catching your illness.

People infected with RSV usually show symptoms within 4 to 6 days after getting infected. Symptoms of RSV infection usually include

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

These symptoms usually appear in stages and not all at once. In very young infants with RSV, the only symptoms may be irritability, decreased activity, and breathing difficulties.

Almost all children will have had an RSV infection by their second birthday.

Call your healthcare professional if you or your child is having difficulty breathing, not drinking enough fluids, or experiencing worsening symptoms.

COVID-19 measures lessened how often we get sick from many other viruses. But one common virus has been on the rise this year. It’s called respiratory syncytial virus, or RSV.

RSV is usually more common in the fall, winter, and spring. But this year, infections have surged over the summer. This is likely because of the lifting of COVID-19 precautions, like masking and social distancing, says Dr. Barney Graham, a physician who studies viruses at NIH.

Almost everyone catches RSV before the age of 2. It’s one of the most common causes of illness in children. But unlike many other viruses that infect the lungs, you can catch RSV over and over again.

“RSV has a number of ways of evading the immune system,” says Graham. “So people are re-infected with RSV on average every three to 10 years.”

RSV infects the cells that line your lungs and breathing passages. Many symptoms mimic the common cold, like a runny nose, loss of appetite, and coughing or wheezing.

Symptoms usually stay mild in older children and adults. But some people are at risk of more serious disease. These include infants, older adults, and people with a weakened immune system.

Some people develop pneumonia or inflammation in the lungs from RSV. Watch for symptoms that get worse over time or trouble breathing or drinking fluids. People with these symptoms should see a health care provider right away. A blood test can show if you have RSV or another virus with similar symptoms.

For mild cases, over-the-counter fever or pain relievers may help reduce symptoms. But people with more serious cases may need treatment in a hospital.

RSV spreads easily between people. It can travel in droplets from a cough or sneeze. It can also stay on surfaces like doorknobs and tables. That means you can catch it if you touch an infected surface and then touch your face.

Most people who get mild RSV feel better in a week or two. But people can still spread it even after they stop showing symptoms.

NIH researchers have been working for decades to develop RSV vaccines. Recently, scientists have been able to take detailed pictures of proteins on the virus’s outer surface. This allowed them to create a vaccine that better targets the virus.

In early research, “this vaccine has turned out to be radically better than any tried before,” Graham says. Researchers hope that a vaccine will soon be available for at-risk groups. Such a shot may be able to protect newborns by vaccinating their mothers before birth, he adds.

An RSV vaccine could do much more than prevent infection, says Graham. Kids who get severe RSV as infants have a higher risk of other lung problems, like asthma. So, a vaccine might prevent some cases of future lung issues as well.

Until there’s a vaccine, good hygiene is the best way to avoid getting RSV and other viruses. See the Wise Choices box for tips on staying healthy.

Protect Against Germs

• Avoid close contact with people who have cold-like symptoms.
• Wash your hands often with soap and water for at least 20 seconds. Use alcohol-based hand gel if you’re unable to wash them. Be sure it contains at least 60% alcohol.
• Clean and disinfect surfaces that are frequently touched, like doorknobs, toys, and mobile devices.
• Avoid touching your face with unwashed hands.
• Cover your coughs and sneezes with a tissue or upper shirt sleeve, not your hands.
• Stay home when you’re sick.

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.

Antiviral medication is not routinely recommended to fight infection. Most RSV infections go away on their own in a week or two. However, RSV can cause severe illness in some people.

Take steps to relieve symptoms

• Manage fever and pain with over-the-counter fever reducers and pain relievers, such as acetaminophen or ibuprofen. (Never give aspirin to children.)
• Drink enough fluids. It is important for people with RSV infection to drink enough fluids to prevent dehydration (loss of body fluids).
• Talk to your healthcare provider before giving your child nonprescription cold medicines. Some medicines contain ingredients that are not good for children.

RSV can cause more serious health problems

RSV can also cause more severe infections such as bronchiolitis, an inflammation of the small airways in the lung, and pneumonia, an infection of the lungs. It is the most common cause of bronchiolitis and pneumonia in children younger than 1 year of age.

Healthy adults and infants infected with RSV do not usually need to be hospitalized. But some people with RSV infection, especially older adults and infants younger than 6 months of age, may need to be hospitalized if they are having trouble breathing or are dehydrated. In the most severe cases, a person may require additional oxygen, or IV fluids (if they can’t eat or drink enough), or intubation (have a breathing tube inserted through the mouth and down to the airway) with mechanical ventilation (a machine to help a person breathe). In most of these cases, hospitalization only lasts a few days.

You can take steps to prevent the spread of RSV. If you have cold-like symptoms, you should:

• Cover your coughs and sneezes with a tissue or your shirt sleeve, not your hands
• Wash your hands often with soap and water for at least 20 seconds
• Avoid close contact with others, such as kissing, shaking hands, and sharing cups and eating utensils
• Clean frequently touched surfaces such as doorknobs and mobile devices

RSV Vaccine for Older Adults

RSV vaccine helps protect adults 60 years and older from RSV disease. Older adults are at greater risk than young adults for serious complications from RSV because immune systems weaken with age. In addition, certain underlying medical conditions may increase the risk of getting very sick from RSV and older adults with these conditions may especially benefit from getting RSV vaccine. If you are 60 years and older, talk to your healthcare provider to see if RSV vaccination is right for you.

Monoclonal Antibody Products that Protect Children from Severe RSV

Two monoclonal antibody products – nirsevimab (Beyfortus) and palivizumab (Synagis) – can help protect babies and young children from severe disease from an RSV infection. Monoclonal antibodies are not vaccines. They provide an extra layer of defense that helps fight RSV infections and protect children from getting very sick. The protection these antibodies provide wanes over time. These products are not treatments for a child who already has RSV infection.

Nirsevimab is recommended for all infants who are younger than 8 months and born during – or entering – their first RSV season (typically fall through spring). One dose of nirsevimab can protect infants for 5 months, the length of an average RSV season. A dose of nirsevimab is also recommended for some children between the ages of 8 and 19 months who are at high risk of severe RSV, such as children who are severely immunocompromised, and who are entering their second RSV season.

Palivizumab is limited to children under 24 months of age with certain conditions that place them at high risk for severe RSV disease. It must be given once a month during RSV season.

CDC recommends all children younger than 8 months receive nirsevimab to protect them in their first RSV season. If your child is at increased risk for severe RSV disease, talk to their doctor to determine if additional doses of monoclonal antibodies are recommended for your child (aged 8 to 19 months) as they enter their second RSV season.

Preventing Severe RSV in Children

If you have cold-like symptoms, ideally you should avoid contact with children at increased risk for severe RSV disease, including children with these health conditions:

• Premature infants 
• Infants, especially those 6 months and younger 
• Children younger than 2 years old with chronic lung disease or congenital heart disease 
• Children with suppressed or weakened immune systems 
• Children who have neuromuscular disorders or a congenital anomaly, including those who have difficulty swallowing or clearing mucus secretions 
• Children with severe cystic fibrosis 

If you can’t avoid contact, carefully follow the prevention steps mentioned above and wash your hands before interacting with children at high risk for severe RSV disease. Don’t kiss them while you have cold-like symptoms.

When possible, parents of children at increased risk for developing severe RSV disease should help their child do the following:

• Avoid close contact with sick people.
• Wash hands often with soap and water for at least 20 seconds.
• Avoid touching their face with unwashed hands.
• Limit the time they spend in childcare centers or other potentially contagious settings during periods of high RSV activity. This may help prevent infection and spread of the virus during the RSV season.