Respiratory syncytial virus (RSV) infects the lungs and airways. It causes colds and is the most common cause of bronchiolitis, a common chest infection that affects infants and toddlers. Most children will have at least one RSV infection by the age of 2. The infection is most severe in young babies and older adults and can cause serious lung infections that may require hospitalization.

Most infants and children infected by RSV typically experience mild symptoms that last a few days. Older children and adults also get RSV but symptoms are typically mild, similar to a common cold. Older adults and those with underlying health conditions such as asthma, chronic heart or lung disease, and those with weakened immune systems, can be at risk of severe illness with RSV.

Through the Respiratory Syncytial Virus Prophylaxis for High-Risk Infants Program, infants and children who are less than 2 years of age at high risk of severe illness from RSV may be eligible for the drug Synagis (palivizumab) used to prevent a serious lower respiratory tract infection caused by the virus.

Key facts

  • Children are more likely catch RSV from November to April (with variations in various regions of Ontario) when the virus is most active.
  • RSV usually causes a mild infection that would not require medical attention or treatment.
  • Most people who get an RSV infection will have mild illness and will recover in a week or two. RSV can also make chronic health problems worse.

Signs and symptoms of RSV

Symptoms of RSV are similar to those of the cold or flu, including:

  • coughing
  • a runny nose
  • fever
  • wheezing
  • a decrease in appetite and energy
  • irritability in children

Because these are common symptoms, it is easy to mistake RSV for other respiratory illnesses, such as the flu or COVID-19. While most RSV symptoms will go away in a few days, seek medical attention if you or your child have trouble breathing, are not drinking enough fluids or are experiencing worsening symptoms.

How RSV is spread

RSV is very contagious and spreads the same way as a common cold by:

  • touching droplets containing the virus after someone coughs or sneezes
  • being close (less than 2 metres apart) to someone with the infection who is coughing or sneezing

After exposure to the virus, it can take 2 to 8 days before becoming sick. People are usually contagious for up to 3 to 8 days. Children are often exposed to and infected with RSV outside the home, such as in school or childcare centers, and can then transmit the virus to other members of the family.

Information for parents

How to treat your child with RSV

In most cases, you can take care of your child with RSV at home as long as they are breathing comfortably, their skin does not look blue and they are drinking and urinating as usual. Most children get better within a week or two.

Because RSV is a virus, antibiotics will not help your child get better faster.

What you can do for your child

Manage fever and pain:


  • it is important that children drink enough fluids to prevent dehydration (loss of body fluids)
  • if your baby is having trouble drinking, try to clear nasal congestion gently with a bulb syringe or with saline (salt water) nose drops


  • a lukewarm bath or wet face cloths will not change your child’s body temperature but may help them feel more comfortable
  • avoid cold baths because they are uncomfortable and can make your child shiver, raising their temperature
  • alcohol baths or rubs are not recommended


  • losing heat through the skin allows the body to cool down and may make your child feel more comfortable
  • dress your child in light clothing
  • if your child starts to shiver, add warmer clothing — remove them when the shivering stops

Talk to your health care provider:

  • before giving your child non-prescription cold medicines, talk to your child’s health care provider
  • some medicines, like over-the-counter cough and cold medicines, contain ingredients that are not good for children

When to go to an emergency department

Some babies and children can develop a severe form of RSV, which may result in pneumonia or bronchiolitis. These illnesses can be serious and your child may need to visit their health care provider or go to the emergency department.

Go to an emergency department if your child:

  • has trouble breathing (working hard to breathe, breathing faster than normal), pale skin, lips that look white or blue, asthma or wheezing
  • is younger than 3 months old and has any of the following symptoms:
    • fever or is very sleepy/difficult to wake
    • repeated vomiting and unable to keep any liquids down for eight hours or more
    • vomiting or diarrhea containing a large amount of blood
    • signs of dehydration with dry mouth or no urination for eight hours or more

Severe RSV infections can result in lung infections or pneumonia in some older adults and those with underlying health conditions. RSV can also lead to worsening of:

  • 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

Adults who experience difficulty breathing should seek immediate medical attention.

How to protect yourself and your child from RSV

  • Stay home: Stay home if you or your child are sick and until you/your child have no fever and symptoms are improving for at least 24 hours (or 48 hours if there was nausea, vomiting and/or diarrhea). Wear a mask when you are outside your home and in public places for 10 days from when your symptoms started.
  • Clean surfaces: Clean surfaces in your home that are touched often on a regular basis.
  • Wash your hands: Wash your hands and your children’s hands often to reduce the spread of germs. Ask others to do the same.
  • Use your arm: Coughing or sneezing into your arm instead of your hands and putting used tissue into the garbage right away.
  • Breastfeed your baby: Breast milk contains antibodies and other immune factors that help prevent and fight off illness.
  • Don’t smoke: Make sure that your child is not around cigarette smoke, especially in your car or home.

If your child is under the age of two years and at high risk of severe illness from RSV, they may be eligible for the drug Synagis (palivizumab) used to prevent a serious lower respiratory tract infection caused by the virus. Please see eligibility here and discuss this option with your child’s health care provider.

Information for Health Care Providers: Respiratory Syncytial Virus Prophylaxis for High-Risk Infants Program

Updated for 2022/2023 RSV season

Through the Respiratory Syncytial Virus Prophylaxis for High-Risk Infants Program, the Ministry of Health covers the full cost of the drug Synagis (palivizumab) used to prevent a serious lower respiratory tract infection caused by the Respiratory Syncytial Virus (RSV) in infants who are less than 2 years of age at the start of the RSV season and who are at high risk for RSV disease.

The drug is only provided during the active season to infants who meet the ministry’s eligibility criteria for funding. The active season is generally from November to April, with variations in various regions of Ontario. The specific start dates for the 2022/2023 season are set out below.

Palivizumab will be funded for RSV prophylaxis in infants who are residents of Ontario, have a valid Ontario Health card and meet one of the following clinical criteria:

  • Infants born prematurely at ≤ 32 completed weeks gestation and aged ≤ 6 months at the start of, or during, the local RSV season; or
  • Infants 33–35 completed weeks gestation and aged ≤ 6 months at the start of, or during the local RSV season, who do not live in remote communities and have a Risk Assessment Tool Score of 49 to 100; or
  • Infants 33–35 completed weeks gestation and aged ≤ 6 months at the start of, or during the local RSV season, and who live in remote communities defined by lack of immediate access to medical care (less than 30 minutes) (i.e., Level I hospital) and/or inability to access pediatric services in a timely manner (less than 90 minutes); or
  • Children less than 24 months of age with Down Syndrome / Trisomy 21; or
  • Children less than 24 months of age with bronchopulmonary dysplasia/chronic lung disease (BPD/CLD; see reference manual for definition of BPD/CLD) and who required oxygen and/or medical therapy specifically for chronic lung disease within the 6 months preceding the RSV season; or
  • Children who were less than 12 months of age and approved for coverage in the previous RSV season for BPD/CLD; or
  • Children less than 12 months of age with hemodynamically significant (HS) cyanotic or acyanotic congenital heart disease (CHD): requiring corrective surgery or are on cardiac medication for congestive heart failure or diagnosed with moderate to severe pulmonary hypertension. Children 12–24 months of age with ongoing HS CHD will be considered on a case-by-case basis.

Infants and children with other specific medical illnesses that place them at high risk of hospitalizations and complications from a RSV infection may also be considered for prophylaxis, if they meet necessary requirements. The enrolment forms for these infants and children will be reviewed on a case-by-case basis by the ministry’s medical consultant(s) with expertise in RSV prophylaxis.

The following are the links to the guidelines, general information, answers to frequently asked questions and applicable forms for the current RSV prophylaxis season for health care professionals:

Information and Guidelines

Update to the start date of the 2022–2023 RSV Season

Please see the following notices regarding changes to the 2022–2023 RSV Season, which ends on March 3, 2023:

Updated for 2022/2023 RSV Season