Vaccination, immunity and records: Your questions on measles, answered

Jennifer Yoon · CBC News

· Posted: Jul 13, 2025 4:00 AM EDT | Last Updated: 8 hours ago

Canada continues to spot an alarming emergence successful measles cases successful 2025.

Through the spring, the microorganism dispersed astir intensely successful Ontario. But aft implicit 2,200 cases, hundreds hospitalized and 1 measles-related death, it seems to beryllium dwindling successful that province.

Now, Alberta's seeing a spike, with astir 1,300 confirmed cases truthful far. 

With each state but Newfoundland and Labrador reporting cases of measles, present are immoderate communal questions from CBC readers, viewers and listeners — answered. 

I've had measles arsenic a child. Am I harmless from getting infected again? 

Most likely yes, says the Public Health Agency of Canada (PHAC).  

It says those who person had a past measles corruption should beryllium immune against different one, arsenic agelong arsenic they person a mean immune response. 

I've mislaid my vaccination records. Should I get different dose?

Generally, yes, says PHAC.

PHAC recommends that children and adults who don't person records of their vaccination past beryllium started connected an immunization docket due to their property and hazard factors.

Even if you've already been vaccinated, it's mostly considered harmless for health-care providers to springiness different dose, PHAC says, due to the fact that they haven't seen further broadside effects from repeated immunization. 

But this is wherefore a nationalist vaccine registry would beryllium hugely helpful, says Dawn Bowdish, a prof of immunology astatine McMaster University. 

"The fig of radical who are looking to fig retired if they got 1 dose, if they got 2 doses, if they were vaccinated arsenic children and possibly they conscionable moved provinces and they can't get their records is highly high." 

Two doses of the measles, mumps and rubella vaccine offer almost 100 per cent effectiveness against the virus in the agelong term.

Can I cheque my immunity to measles?

That depends. 

PHAC says regular investigating for laboratory grounds of measles immunity is not recommended for the wide population. 

Some populations, similar health-care workers who enactment with susceptible people, arsenic good arsenic immoderate large women, tin get a humor trial looking for antibodies against measles.

Those who person received 2 doses of a measles-containing vaccine, oregon those who are calved earlier 1970, are presumed to beryllium immune against the virus. 

Do we surface for measles vaccination presumption among radical who participate Canada? 

No. Proof of vaccination is not mandatory to enter Canada. 

Canada does necessitate imperishable residents and definite impermanent residents to person an migration aesculapian exam earlier arriving successful Canada, said a spokesperson for Immigration, Refugees and Citizenship Canada. The trial besides screens for definite communicable diseases. 

During that aesculapian exam, immoderate whitethorn beryllium offered vaccinations — including the measles, mumps and rubella shots. 

Doctors who enactment with recent immigrants and asylum seekers tell CBC News their patients generally don't hesitate to get immoderate puerility vaccinations they mightiness person missed. 

But, they say, the national authorities tin bash much to ramp up pre-departure vaccination programs, and make it easier for health-care providers to entree aesculapian and vaccination records crossed borders.