Measles is a respiratory infection that is very contagious. It spreads when you breathe in the air after someone with measles coughs or sneezes, or by touching your eyes, nose or mouth after touching an infected surface. Measles is one of the most contagious respiratory infections.
Symptoms of measles include:
What are the complications of measles?
Measles can lead to serious health problems, such as:
Who is at risk of complications from measles?
If you are NOT fully vaccinated (2 lifetime doses of MMR) or have not had a measles infection in the past:
If you believe you or your family may have been exposed to measles and have not been vaccinated (or have not had a measles infection in the past), isolate and contact your health care provider or local public health department immediately for guidance.
If you are fully vaccinated or immune to measles:
It is very unlikely that you will develop the disease. As a precaution, watch for measles symptoms until 21 days after you are exposed.
Your child may have received 1 or 2 doses depending on their age and immunization schedule.
The efficacy of a single dose of measles vaccine given at 12 or 15 months of age is estimated to be 85% to 95%. With a second dose, efficacy is almost 100%. Measles vaccines: Canadian immunization guide - Canada.ca
The first dose of MMR vaccine is administered at around 12 months of age.
Breastfeeding may provide some passive antibodies and other immune benefits, but it does not provide reliable protection against measles infection.
MMR vaccine can be given as young as 6 months of age, if needed.
Infants and Children
Routine childhood immunization: 2 doses of any measles-containing (MMR or MMRV) vaccine. The first dose of measles-containing vaccine should be administered at 12 to 15 months of age and the second dose at 18 months of age or any time thereafter, but no later than around school entry.
Children and adolescents who are previously unimmunized: 2 doses of measles-containing vaccine. MMRV vaccine may be used in healthy children aged 12 months to less than 13 years.
Adults
Susceptible adults born in or after 1970: 1 dose of MMR vaccine. Those who are at the greatest risk of measles exposure (travellers to destinations outside of Canada, health care workers, students in post-secondary educational settings, and military personnel) should receive 2 doses of MMR vaccine.
Susceptible health care workers and military personnel born before 1970: 2 doses of MMR vaccine.
Susceptible travellers to destinations outside of Canada born before 1970: 1 dose of MMR vaccine.
Susceptible students in post-secondary educational settings born before 1970: 1 dose of MMR vaccine should be considered.
For your child or teen, you can look up their Toronto Public Health vaccination record. Please keep in mind that if documentation of vaccines was not submitted to Toronto Public Health they will not show in their record.
For adults: it is unlikely that we have your childhood vaccines on record with us. Most people receive MMR during childhood. If you still wish a copy of your vaccine record, understanding that MMR doses you may have received as a child may not appear, contact our clinic:
Updated July 3, 2026