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Respiratory Syncytial Virus (RSV)

​​What is RSV?

Respiratory syncytial virus (RSV) infects the lungs and airways. It causes colds and is the most common cause of bronchiolitis in young infants and toddlers. Most children will have an RSV infection by the age of 2. Children are more likely to catch it during the RSV season, from November to April, when the virus is most active. Most children will have a mild infection and not require any medical attention.

Respiratory System
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RSV can be spread by touching:
  • mucus from the nose or mouth of a person who has the virus
  • soiled tissues, surfaces, clothes, and toys a person with the virus has touched
  • the unwashed hands of a person with the virus

RSV can live on countertops and other hard objects for more than 6 hours. It can live on clothes and hands for up to 1 hour. After someone is exposed to RSV, it can take 2 to 8 days before they become sick from the virus.

Signs and symptoms caused by RSV

A baby or child with this infection may:

  • cough
  • have a runny nose
  • have a fever
  • sometimes wheeze

Because these are common symptoms, it is easy to mistake RSV for the flu or another virus.

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 peeing as usual. The infection usually last a few days.

In healthy adults, RSV is often not serious. But adults can pass the virus to children.

RSV can be s​erious

Some babies and children can develop a severe form of RSV. This may be pneumonia or bronchiolitis. These illnesses can be serious. Your child may need to visit your family doctor or paediatrician, or go to the emergency department.

Your baby or child may have a higher risk of getting very ill from RSV if:

  • your baby was born prematurely (before 33 weeks of pregnancy) and is less than 6 months old when the RSV season starts in November.
  • your child is less than 2 years old and has certain lung conditions, congenital heart disease, Down’s syndrome​ or has problems with their immune system. Your child’s doctor will speak to you about this.
  • your child has other specific medical problems that your doctor will talk to you about.

Preventing RSV

Do not expose your baby to cigarette smoke. Smoking has been associated with increased infection rates.

You can help stop the spread of RSV by:

  • washing your hands with soap and water or by using alcohol-based hand sanitizer before and after touching your child. Ask others to do the same.
  • coughing or sneezing into your sleeve instead of your hands and putting used tissue into the garbage right away.
  • avoiding kissing or similar close contact with your baby’s face and hands when you are unwell.
  • staying away from your hospitalized premature baby if you are sneezing, coughing or have a runny nose or a fever.
  • keeping your baby away from crowds and anyone with sneezing, coughing, a runny nose, or a fever, especially during RSV season (from November to April). Infections spread more easily when there are more people around.
  • cleaning surfaces in your home that are touched often on a regular basis, more often during RSV season.

Babies at high risk need medicine during RSV season

No medicine can stop your baby from catching RSV and getting RSV once does not prevent infection. The average person may have an RSV infection multiple times during their lifetime.

There is no vaccine available for the general public yet. But there is one medicine that can help prevent RSV from becoming very serious and it is recommended for babies at high risk of serious RSV infection. Your health care provider will decide if your child needs this medicine. The name of the medicine is palivizumab (say: pal-ee-VEE-zu-mab). The brand name is Synagis. This treatment is sometimes called RSV prophylaxis (say: pro-full-AX-iss), which means "prevention".

Palivizumab is given by a needle (injection) into a muscle. It does not interfere with normal childhood immunizations. This medicine works by giving your baby antibodies that help fight an RSV infection. These antibodies help reduce the chances that an RSV infection will become severe.

A palivizumab dose works for about 30 days. This means that your child needs a dose of the medicine every month during RSV season. If you delay or skip the next appointment, the medicine stops working. Your child will no longer be protected against the virus.

Reactions ar​e rare

The most common side effects of palivizumab are fever, rash or redness at the injection site. Serious allergic reactions are very rare. Ask your baby's doctor or nurse for the most recent information.

Remind your baby's doctor or nurse if your baby needs medicine to prevent RSV

Your baby can take the medicine in the hospital, the doctor’s office or an RSV clinic. A doctor or a nurse can give it.

To help your baby get the right treatment each month, you should:

  • Keep notes of the dates of the treatment. Use your baby’s regular immunization card to keep track. You can also print out the tables below to help you keep track of your baby’s treatment.

RSV prophylaxis




Dose #1

Dose #2

Dose #3

Dose #4

Dose #5

Dose #6

Positive tests for RSV and RSV hospitalizations



RSV positive

RSV admission to hospital

Discharged from hospital

  • Re​mind your baby’s doctor or nurse that your baby needs the medicine once a month during RSV season.

Visit the Ministry of Health of Ontario website has more information about RSV prophylaxis.


When a child is fighting RSV, treatment is mainly to relieve the symptoms. Antibiotics have no effect on viruses. They will not help your child get better faster.

Key points

  • RSV is a virus. It is very common and causes mild symptoms in most infants and children. It can cause serious lung infections in some babies and children.
  • You can help prevent spreading the virus by regularly washing your hands, avoiding close contact with your baby if you are unwell, keeping your baby away from sick people.
  • If your baby is at high risk for serious lung infections, your baby will need treatment once a month during RSV season (November to April).
  • You can help by reminding your health care provider that your baby needs the medicine. Use the tables to help you keep track.

Andrea Riekstins, RN, MN, APN

Arlene Chaves, RN, MN, APN

Allan Coates, MD, CM

Brenda O'Doherty, R​N

Krista Keilty-Lau, MN, APN

Marilyn Cranis, RN​

Theo J Moraes, MD, PhD, FRCPC