Measles

Description
  • Measles is a very contagious virus that lives in the nose and throat of an infected person. 
  • It can spread very easily through the air from an infected person when they breathe, talk, cough or sneeze. 
  • Vaccination offers the most effective protection and the measles, mumps and rubella (MMR) vaccine has proven to be one of the safest and most effective vaccines available.

Measles in Ontario - 2025

Thunder Bay District

  • Case: TBDHU is reporting a case of measles with case and contact management underway (May 9, 2025)
  • Exposures: See below for a list of locations where the public may have been exposed to the measles virus as well as directions from public health, including monitoring for symptoms.

Cases are increasing across Ontario

  • Cases are rising in Ontario and the current rate is the highest the province has seen in the last 10 years.
  • Some cases are in hospital due to their infection.
  • Over 96% of these cases are not immunized or have unknown immunization status.
  • Places visited by recent measles cases while they are infectious (can spread the infection) are listed on Public Health Ontario's website.
  • Cases are also increasing across the country as well as internationally.

Vaccine protection is the best protection

  • Those travelling are recommended to make sure their vaccination status is up to date.
  • Learn more about vaccine recommendations below.

Health care provider information

TBDHU is advising people of  locations where the public may have been exposed to the measles virus: 

Sunday May 4, 2025

  • Air Canada flight AC1195 – Toronto to Thunder Bay 9:40 pm – 11:00 pm
  • Thunder Bay International Airport (YQT) terminal building 11:00 pm – 1:30 am

Wednesday May 7, 2025

  • Harbourview Family Health Team 10:40 am – 1:15 pm
  • LifeLabs Oliver Road. 11:15 am – 1:45 pm

Thursday May 8, 2025

  • Port Arthur Health Centre (including Shoppers Drug Mart) 10:30 am – 2:00 pm
  • LifeLabs Port Arthur Health Centre 10:30 am – 2:00 pm

TBDHU advises anyone who may have been exposed to the measles virus at the above locations to follow the instructions below.

1. Check your vaccination record to ensure you are protected from measles

  • People born before 1970 are considered immune, as measles was widely circulating at that time. In addition, these individuals may have received measles vaccine at some point.
  • Anyone born in 1970 or later should check their vaccination record to ensure they are protected from measles. They require two doses of a measles vaccine to be considered protected. Those unsure of their vaccination status are asked to contact their healthcare provider by phone or e-mail.

2. Monitor for symptoms until:

  • May 25, 2025 if exposed May 4th
  • May 28, 2025 if exposed May 7th
  • May 29, 2025 if exposed May 8th 

Symptoms can include:

  • fever, runny nose, cough, red eyes
  • small spots with white centres that appear inside the mouth
  • a red blotchy rash appears on the face then spreads down the body (normally appears 3 to 7 days after symptoms begin) . 

Individuals should monitor for symptoms even if they are vaccinated against measles. If symptoms develop, individuals should seek medical care and testing and should largely stay home until the results are back. Call ahead to clinics so precautionary measures can be taken. 

 

Measles is vaccine preventable

Over 96% of the 2025 cases in Ontario were not vaccinated or did not know if they were vaccinated against measles.

The measles, mumps and rubella (MMR) vaccine has proven to be one of the safest and most effective vaccines available, even if the vaccine was received many years ago.

Measles protection is required to attend both licensed child care and school in Ontario.

The MMR vaccine is FREE through Ontario’s publicly funded vaccine program. MMR vaccines are offered to children and adults as part of Ontario’s routine vaccine schedule

ROUTINE

  • Children should receive one dose at 1 year of age and a second dose at 4 years of age.
    • It is recommended that children receive the second dose (booster) as soon as they turn 4.
  • Adults born in or after 1970 should have record of receiving at least one dose and may consider speaking to a health-care provider about receiving a second dose.
  • Health care workers and post-secondary students should have record of receiving two doses.

NOTE:

  • Adults born before 1970 are generally considered immune to measles as measles was widely circulating at that time. In addition, these individuals may have received measles vaccine at some point.
  • Those who are breastfeeding can safely receive the vaccine and pass on antibody protection to their child through breast milk.
  • Pregnant people cannot receive the vaccine.

TRAVELLING

Make sure you and your family members are vaccinated BEFORE travelling to an area where there are ongoing cases of measles:

  • Infants 6-11 months should receive 1 dose. To be fully protected and stay on track with their routine vaccines, these infants will need to receive a dose at their first birthday and a second dose at 4 years of age.
  • Children between 1 and 3 years of age who have already received their first dose according to the routine schedule should get their second dose. There must be at least 4 weeks between the doses.
  • Children 4 years of age or older should get their second dose if they have not already received it as part of the routine schedule.
  • Adults born in or after 1970 should get a second dose if they only have record of one dose.
  • Adults born before 1970 should get one dose if they have never been exposed to measles and do not have history of getting a dose in the past.

To identify the areas with ongoing cases of measles:

EXPOSED TO MEASLES

Were you exposed to the measles virus at one of the locations identified by TBDHU?

  • Adults born before 1970 are considered immune, as measles was widely circulating at that time OR they may have received measles vaccine at some point.
  • Anyone born in 1970 or later should check their vaccine record to as they require two doses of a measles vaccine to be considered protected. Not sure, see the section below "Unsure if you need a dose"?.

 

 

For Further Information

Questions about the vaccine? Call the Vaccine Preventable Diseases (VPD) Program at (807) 625-5908 or toll-free at 1-888-294-6630.

Questions about measles? Call the Infectious Disease Program at (807) 625-8318 or toll-free at 1-888-294-6630.

Health Topic
Diseases & Infections
Immunizations
Travel