Vaccinations suggested to stop measles spread
Nikita Mohile
Since the beginning of the year, Ontario has recorded over 400 cases of measles. This resurgence in a disease that should essentially be a thing of the past is, according to an infectious disease specialist from Markham Stouffville Hospital, "multifactorial," but largely due to "big pockets of the population that are not fully vaccinated."
Dr. Valerie Sales says that communities with a vaccination rate of 95 per cent will have “herd immunity,” limiting the virus from spreading.
A rash is just one of the many symptoms of measles.
Measles is one of the rare diseases that can be eradicated from the earth with vaccination. In 1998, with good recorded vaccination rates, Canada was said to have eliminated measles. In fact, according to a report by Public Health Ontario, 85.1 per cent of measles cases since October 2024 have occurred in unvaccinated people.
"Vaccines are one of the most important public health intervention that we can do to prevent illness," says Sales.
In Ontario, babies receive the first dose of the measles vaccine at 12 months, or from six months onward if travelling to high risk areas, and the second dose between 4-6 years of age. Public Health requires students to be fully immunized against measles, with exemptions allowed for religious and medical reasons. With COVID, Public Health was not able to review vaccination records to ensure students were caught up on their vaccinations.
People born before 1970 are considered to have immunity through illness or boosting exposure to the virus after vaccination, as the virus was circulating. Additionally, those born between 1970 and 1996 likely have received only one dose. If infected, they can present with a possibly milder yet still contagious case of measles.
"Everybody should be looking at their vaccine booklet or checking with their doctor to see if they've had both shots," says Sales. "If they have not or do not have the records, they should just get the vaccine, unless they are immunosuppressed or pregnant—there's no harm in getting more doses."
Another factor contributing to the current outbreak is international travel. Imported measles cases can spread within communities and have lead to the current outbreak. When travelling, there's more chance of exposure to different illnesses, says Sales. To prevent infection, health officials recommend visiting a travel clinic or seeing a family doctor before departure to ensure all necessary vaccines are up to date, and to have malaria medications if needed.”
Why is it so crucial to prevent measles? The disease is extremely contagious and one of the "rare infections that is truly airborne." The virus spreads through aerosols expelled when one speaks, sneezes, coughs, laughs, or even exhales. If one person has measles, 90 per cent of non-immune people around them will be infected. Those exposed to measles experience a delay before noticing symptoms. During this 7-18 day incubation period, infected individuals can spread the disease to others starting one day prior to the fever.
Measles presents with cold-like symptoms, including fever, cough, runny nose, red watery eyes, for 3-7 days until a characteristic rash appears on the face and moves downward. There is risk of severe complications especially for young children, pregnant women and the immunocompromised. This includes pneumonia, inflammation of the brain (encephalitis) with possible long -term problems such as deafness or seizure disorder. Since October 2024, 34 outbreak cases of measles were hospitalized, including two in the ICU.
Dr. Sales also emphasized that suspected cases should be reported to Public Health Ontario to initiate contact tracing immediately. At risk contacts identified in the first 3 -6 days can be given post-exposure vaccines or antibodies that can prevent severe disease. There is no known cure for measles.