Respiratory Syncytial Virus

Respiratory syncytial virus (RSV) is a common cause of respiratory infections, particularly in children.

​​​​​​It is the most common cause of bronchiolitis, meaning inflammation of the small airways in the lung. It is also a common cause of pneumonia, an infection of the lungs, among infants and young children.

RSV causes outbreaks of respiratory illness each year. In British Columbia, RSV infections often occur between the late fall to the early spring.

Information for health care professionals

 

RSV is a respiratory virus that affects the lungs and airways.

 

Symptoms can begin about 3 to 5 days after a person is first exposed to the virus.

Older children and adults usually present with symptoms similar to the common cold and symptoms go away in 1 to 2 weeks. Typical RSV symptoms include:

  • Runny nose
  • Cough
  • Low grade fever (less than 38.5° C or 101° F)
  • Loss of appetite
  • Mild sore throat

In very young infants  the only symptoms may be irritability, decreased energy, and breathing difficulties.

Symptoms can worsen if the virus induces inflammation of the lungs. In the case of a more serious infection, symptoms could include:

  • Difficulty breathing or rapid breathing
  • Unusual or prolonged pauses of breathing
  • Wheezing
  • Difficulty feeding

 

RSV is highly contagious, meaning it spreads easily from person to person. RSV is spread to others through breathing, coughing, and sneezing. The virus can also spread when a person touches tiny droplets from coughs, or sneezes on another person or on an object, and then touches their own mouth or nose before washing their hands.

People infected with RSV are usually contagious for 3 to 8 days. However, some people with weakened immune systems may spread the virus for up to 4 weeks after there symptoms have cleared.

 

In older children and healthy adults, illness is usually mild and similar to the common cold. However, in some cases, RSV can cause more severe infections such as bronchiolitis (inflammation of the small airways in the lungs) and pneumonia (an infection of the lungs)​.

Premature babies, children younger than 6 months of age, children with chronic respiratory or cardiac conditions, older adults, and people with weakened immune systems are at increased risk of severe RSV and may need to be hospitalized.

 

Health care providers suspect and test for RSV infection in young infants and children who have bronchiolitis or pneumonia during RSV season or during an outbreak of RSV in their area.

Testing may be recommended if healthcare providers are trying to identify an outbreak or if a patient requires hospital care. A sample of mucus from the patient’s nose is often used to test for the virus.

 

For most people, RSV goes away on its own in a week or two, and home treatment is all that is needed. This may include:

  • ​Fever and pain management with acetaminophen (Tylenol®) or ibuprofen (Advil®). Don’t give acetylsalicylic acid (e.g., Aspirin®) to anyone under age 18
  • Drinking enough fluids to prevent dehydration
  • Clearing your baby's nasal passages with a suction device if breathing difficulties interfere with feeding or sleeping

Antiviral medication is not routinely recommended.

When to see a doctor

If you or your child seem to have worsening symptoms, with more rapid breathing, wheezing, high fever or increased feeding difficulty, you should seek medical care. If an adult or child is experiencing severe breathing distress, seek urgent medical care. Call 9-1-1 or go to your nearest emergency department.

 

You can reduce the risk of getting RSV or spreading it to others by:

  • Washing your hands with soap and water or using hand sanitizer
  • Covering your coughs and sneezes with your sleeve or a tissue
  • Staying home or away from others if you feel sick
  • Keeping away from people who have respiratory tract infections whenever possible

It is also known that keeping your children away from second hand smoke helps prevent RSV infections and reduces its severity.

Breastfeeding/chestfeeding your baby for as long as you can also offers protection against RSV infections.

​For additional tips and tools to help protect you and your family from respiratory illnesses, check out the Personal Toolkit for cold and flu season (PDF).

RSV vaccines for older adults


Two RSV vaccines, AREXVY™ and ABRYSVO™, are available to protect older adults from RSV.

Canada’s National Advisory Committee on Immunization recommends the RSV vaccine for: 
  • Adults 75 and older, especially those at higher risk of severe RSV disease
  • Adults 60 and older living in nursing homes or other chronic care facilities
Adults 50 to 74 who are not in these groups can talk to their health care provider to see if the vaccine is right for them. 

The vaccine is given as one dose, ideally just before RSV season begins. In Canada, RSV season is in the fall and winter, when the virus is most active.

This vaccine is not free. It costs about $300 and is available at select pharmacies and travel clinics. Some health insurance plans may cover the cost of the vaccine. Check with your provider. 

RSV protection options for infants and young children


There is currently no RSV vaccine approved for infants and young children. However, two products can help protect them from severe RSV:
  • RSV vaccine for people who are people – ABRYSVO™
  • BEYFORTUS® (nirsevimab), a monoclonal antibody medicine for certain infants and young children at higher risk

RSV vaccine for people who are pregnant


In December 2023, Health Canada approved ABRYSVO™ for people who are pregnant to help protect babies from severe RSV after birth.

The vaccine works by helping your body make antibodies (proteins that help fight germs) against RSV. These antibodies pass to your baby through the placenta before birth and help protect them after birth for at least 6 months.

It is given before or during RSV season, between 32 and the end of 36 weeks of pregnancy. It works best if given at least two weeks before birth, so the antibodies have time to reach your baby.  In BC, most (90%) infants will not be eligible for BEYFORTUS® (nirsevimab) and will rely on the vaccine to protect them against RSV in their first months of life.  

In B.C., the cost of the RSV vaccine is generally not publicly covered. It is covered by First Nations Health Authority for eligible pregnant individuals​​. Otherwise, it costs about $300 and is available at select pharmacies and travel clinics. Some health insurance plans may also cover the cost of the vaccine. Check with your provider.

​BEYFORTUS® (nirsevimab) for certain infants


BEYFORTUS® (nirsevimab) is a type of medicine called a monoclonal antibody that helps protect babies from severe RSV.

Unlike vaccines, which help the body make its own antibodies, BEYFORTUS® (nirsevimab) provides protection by giving antibodies directly to your baby through a single injection. Given just before or during RSV season, it protects for the entire season.

In BC, BEYFORTUS® (nirsevimab) is offered only to certain infants and young children under 2 years old during or just before RSV season, who are at high risk for severe illness. It is provided through the BC Infant RSV Immunoprophylaxis Program. Examples of eligible children include: 
  • Some premature babies
  • Infants and young children with certain chronic medical conditions
  • Infants under 6 months living in remote communities where health care access is more limited or living in congregate settings like supportive housing.
Many eligible babies receive the medicine before leaving the hospital, while others may get it at a public health clinic or community health centre. Families of eligible infants and young children may be contacted by a health care provider. 

Both products — the vaccine for people who are pregant (Abrysvo™) and BEYFORTUS® (nirsevimab) — can greatly reduce the risk of severe RSV infection and hospitalization in young infants. Talk to your health care provider about which RSV protection option is right and available for your baby.