Measles is a highly contagious virus that lives in the nose and throat mucus of an infected person. It can spread very easily from an infected person when they:

  • breathe
  • talk
  • cough
  • sneeze

The measles virus can remain in the air or on surfaces for up to 2 hours. People can become infected if they breathe the contaminated air or touch the infected surface, then touch their eyes, nose or mouth.

Infection or exposure to measles

If you think you or a family member has the measles, or you think you’ve been exposed to measles:

  • call your health care provider immediately – do not go to a health care facility or office without calling ahead first
  • tell your health care provider you may have measles or may have been exposed to the virus
  • if it is recommended you be seen in person, the proper precautions will be made to prevent the spread to others


Measles symptoms begin 7 to 21 days after exposure to the virus and include:

  • fever
  • runny nose
  • cough
  • drowsiness
  • irritability
  • red eyes
  • small white spots can appear on the inside of the mouth and throat but are not always present
  • a red blotchy rash appears on the face and then spreads down the body (normally appears 3 to 7 days after symptoms begin)

Most people fully recover from measles within 2 to 3 weeks, but measles can sometimes cause complications, such as:

  • pneumonia
  • ear infections
  • diarrhea
  • hearing and vision loss
  • brain swelling (encephalitis)
  • seizures
  • death

Getting a vaccine

If you are unsure of whether you or your family are fully protected against measles, talk to a health care provider or public health unit.

Vaccination is the most effective way to prevent the virus. The measles vaccine is publicly funded and available at your health care provider’s office or through some local public health unit immunization clinics.

In Ontario, the measles vaccine is available as a:

  • measles, mumps and rubella (MMR) vaccine
  • measles, mumps, rubella and varicella (MMRV) vaccine


Infants 6 to 11 months of age should get a dose if they are travelling to an area with increased measles activity.


Children should get two doses of the measles vaccine – a dose of MMR vaccine at 1 year of age and a dose of MMRV vaccine between 4 and 6 years of age (preferably prior to school entry).


Adults who have not been given an MMR vaccine can be immunized as well.

Adults should receive:

International travel to areas with measles activity

  • Individuals traveling to areas where measles outbreaks are occurring should make sure their immunizations are up to date. Talk to a health care professional at least 6 weeks before travelling to make sure you are fully protected against measles.
  • See Travel Health Notices for information on measles activity internationally.

Checking your vaccine records

You should regularly check your and your families’ personal immunization record, or "Yellow Card," to see if you or your family has received the necessary dose(s).

If you have lost your card, do not have one, or are not sure of your vaccination status, talk to your health care provider or call your local public health unit.

Individuals without record of receiving a vaccine may be considered unimmunized and can receive dose(s) of the MMR or MMRV vaccine as indicated in the immunization recommendations section.

It is safe to receive doses of either the MMR or MMRV vaccine even if you have received these vaccines previously. People who have developed a serious reaction after receiving a vaccine should speak to their health care provider before receiving additional doses of that vaccine.

Keep your child’s records in a safe place.

Reporting your vaccine records

Every time your child gets a vaccine from their health care provider, you need to report your child’s updated immunization records to your local public health unit. Your health care provider does not report these records for you.

After you or your child receives any immunization, make sure your health care provider updates the personal immunization record, the "Yellow Card".

Use the Immunization Connect Ontario (ICON) tool to update and view your child’s immunization records. You can access this tool through your local public health unit's website.

Once your child’s vaccination record is complete in ICON, you can access a copy of their vaccination record at any time, including generating an electronic yellow vaccination card when proof of vaccination is required.

Determining your previous measles vaccine history

Individuals who received doses according to Ontario’s immunization schedule, would have generally received:

  • one dose of measles-containing vaccine, if born from 1967 to 1976
  • two doses of measles-containing vaccine, if born on or after 1977

Adults born before 1970 are generally presumed to have acquired immunity from past exposure to the measles virus. However, some remain susceptible and should be immunized if they are unsure if they had measles or the vaccine.

Vaccine safety

The measles vaccine is very safe and effective. There is no evidence that the vaccine causes autism and is safe for people who live with individuals who are immunocompromised or pregnant.

Most individuals do not have any side effects from the vaccine. The side effects that may occur are usually mild and go away on their own. Side effects may include:

  • soreness, redness, or swelling where the vaccine was given
  • fever
  • mild rash
  • temporary pain and stiffness in the joints

More serious side effects are rare. These may include high fever that could cause a seizure.

Breastfeeding individuals can receive the MMR vaccine not only to protect themselves, but to prevent them from passing the virus to their baby or other family members. In addition, antibodies have been shown to pass in breastmilk following immunization which may protect babies against measles.

Who should not get the vaccine

There are some groups who should generally not be given the vaccine such as, but not limited to people who:

  • are pregnant (people of childbearing age should be advised to avoid pregnancy for at least 1 month following immunization with MMR vaccine)
  • have a history of anaphylaxis after previous administration of the product (or components of the vaccine)
  • have medical conditions that may be contraindicated (for example, individuals with history of convulsions, certain immunosuppressant medications, congenital or hereditary immunodeficiency)

Speak with your health care provider or local public health unit about the benefits and risks of the vaccine, or if you have problems with your immune system.


There is no specific treatment for persons with measles. However, the following measures reduce the risk of infection among people who have been exposed:

  • unimmunized persons over 6 months of age or persons who have received only one dose of measles-containing vaccine and who have been exposed to measles may be protected if they receive a dose of MMR vaccine within 72 hours from exposure.
  • people who are at high risk (young infants, pregnant people and immunocompromised) can receive immunoglobulin (a substance made from human blood plasma that contains protective antibodies) within 6 days of exposure.

Schools and licensed child care centre requirements

If the public health unit does not have required immunization records or a valid exemption for your child, they may be temporarily suspended from school until the required records are provided. In this case, parents will receive notification from the health unit during the school year with enough advance notice to report the records or have their child immunized, in order to avoid suspension from school.

Children who are exempt from immunization are at increased risk and may not be permitted to attend school during a disease outbreak.

Any child attending a licensed child care centre is required to be immunized according to their age and what they are recommended to receive as part of the immunization schedule unless they have a valid exemption.