Everything you need to know about protecting yourself against measles
'This is not a disease you want to give a very young infant,' says Dr. Zain Chagla
Vancouver resident Stefania Seccia has a stern message for parents: Get your children vaccinated against measles.
Seccia went through a major health scare in 2019 when a B.C. Children's Hospital nurse called to tell her that her nearly one-year-old son Max might have been exposed to measles after a recent hospital visit.
"The nurse was like, 'Because of when you went, we can't guarantee that your son was not exposed to measles while you were in the waiting room,'" Seccia said.
Days after receiving the call from the hospital, Seccia learned that the father of the children at the centre of the outbreak at B.C. Children's Hospital didn't vaccinate his children before a trip to Southeast Asia because of disproven evidence linking the measles vaccine to autism.
Seccia quickly decided to share her experiences with news media.
"We see this news story about this person who made a really reckless choice that now has my son potentially in an extremely dangerous situation … so that's why we went to the news," Seccia said.
Max — who was a high-risk patient because he was born prematurely — never developed measles, and Seccia was able to quickly schedule an appointment for a measles, mumps and rubella (MMR) vaccine.
As measles cases rise around the world — and appear in countries like Canada with ready access to life-saving vaccines — Seccia is one of a chorus of voices urging parents to vaccinate their children and adults to get their shots, too.
What is measles?
Measles is a highly contagious infectious disease caused by exposure to measles virus, says infectious diseases specialist Dr. Zain Chagla. The disease is spread through direct contact with infectious droplets, or through airborne spread by an infected person.
"This is an infection, realistically, that is one of the most infectious, in terms of spread pathogens, known to man," Chagla, who serves as co-medical director of infection control at St. Joseph's Health Care in Hamilton, told The Dose host Dr. Brian Goldman.
Not only can the virus remain in an environment for up to two hours after an infected individual has left the scene, but Chalga says one infected patient can also transmit the disease to up to 20 other people.
Measles has an incubation period of roughly 10 days, and patients who contract measles initially show symptoms similar to a common respiratory infection, such as the cold or flu.
They'll develop a cough and a runny nose, as well as redness in their eyes. After a few days, however, a "characteristic rash" begins to emerge around the face, slowly working its way down a patient's neck before it spreads further, said Chagla.
"Red spots that start on the face start becoming much more apparent on the face, to the point where they almost form a single layer of redness going down into the neck and then down into the rest of the body."
While the presence of the rash is typically enough to alert patients that they've contracted measles, Chagla said the virus is contagious soon after experiencing the initial flu-like symptoms.
"It's only until the rash shows up, which is actually towards the end of the infectivity of this illness, where they finally have characteristic symptoms that then prompts health-care attention," he said.
"Unfortunately, the exposures have happened and it's too late."
Before the introduction of effective vaccines that prevented measles infection and transmission, the disease was considered a childhood illness from which most people would eventually recover.
However, Chagla said, the disease can cause brain injury, hearing loss and developmental delays. In some instances, it can also cause immunodeficiencies against other illnesses after patients have recovered from a measles infection.
"This is not a disease you want to give a very young infant."
Modern MMR vaccine developed in 1971
Though the first measles vaccine was licensed for public use in 1963, it wasn't until 1971 that the modern MMR vaccine capable of protecting against measles, mumps and rubella was developed, according to the World Health Organization (WHO).
Today, the MMR vaccine is administered as a two-shot series, with children receiving their first dose around the age of one and their second dose between the ages of four and six. Children under the age of 12 months who travel to known measles hotspots can also receive a vaccination.
Health Canada recommends waiting a minimum of four weeks between the first and second dose.
People born prior to 1970 are expected to have acquired and recovered from measles, according to Chagla, and it's possible they weren't vaccinated at all. People born after 1970 have likely never acquired measles because of successful public health efforts to combat the disease.
Additionally, the measles vaccine was offered as a single shot until 1996, when the the two-shot series was introduced.
"So there's people [born] between 1970 and 1983 that may not have been offered a vaccine that should be considering getting it," said Chagla.
People born between 1983 and 1996 might "have got one dose of vaccine, but not a second," he added.
Health Canada numbers show that roughly 87 per cent of Canadians have at least one dose of the measles vaccine.
"I'm part of the cohort that only had a single dose," said Dr. Sumon Chakrabarti, an infectious diseases specialist at Trillium Health Partners in Mississauga, Ont., who received his first dose in 1979 and a second dose in 2010.
"Now the primary series is two doses, and this is what the vast majority of people have, but there are people who haven't had a second dose."
Individuals who've only received a single dose, as well as people who were infected with and recovered from measles before vaccines were available, should still get an updated dose, said Chagla.
"Two doses gives you optimal protection."
Additionally, Canadian public health guidelines state that someone infected with measles can get a dose of vaccine within 72 hours of exposure.
Measles cases on the rise
Despite the widespread availability of measles vaccines in developed countries, public health experts are tracking a growing number of cases in higher-income European countries such as the U.K., Austria and Belgium.
According to data published by the WHO, Europe saw a 30-fold increase in measles cases in 2023 compared to 2022. Europe had 941 cases in all of 2022, compared to more than 58,000 reported cases in 2023, according to the WHO.
Chagla is quick to point out that measles case rates in Canada are significantly lower than those in Europe and even the U.S. There have been fewer than 20 reported cases of measles in Canada in 2024, to date, according to the Public Health Agency of Canada's weekly measles and rubella tracking reports.
At least four cases have been reported in Ontario alone, with one recent case being investigated where the cause of infection is "unknown," according to local public health officials. At least seven cases have been identified in Quebec, with public health officials in Laval warning that community transmission may have been possible. One case has also been confirmed in B.C.
Chagla said travellers in particular need to be especially cautious because the illness has largely become a "travel-associated disease."
"And it's not simply travel to low-income and middle-income nations. This is travel to places in Western Europe, which are fairly common for Canadians to visit," he said.
Chagla said disproven evidence linking MMR vaccines to autism, routine childhood vaccinations missed as a result of the COVID-19 pandemic, as well as vaccine hesitancy spurred by the pandemic are among the reasons responsible for the current state of measles cases in developed countries.
According to an Angus Reid poll released Wednesday, 17 per cent of survey respondents who identified as parents of minors said they are "really against" vaccinating their children, compared to four per cent in 2019.
In contrast, 67 per cent of respondents said they would vaccinate their own children "without reservation," compared to 72 per cent of respondents in 2019 who said they would vaccinate their kids.
"We have a number of people that may have been on the fence about childhood vaccines, where COVID-19 vaccines then increased their hesitancy, that are choosing to reduce their vaccines for their children," Chagla said.
"Then globally … due to a significant issue with health-care utilization during this time, as well as escalating conflicts in many areas of the world, this unfortunately has led to generations of children not having access to vaccines."
For his part, Chagla said Canadian immunization rates are reassuring, adding that the lack of confirmed person-to-person spread "is a testament to our wall of immunity."
"But as that wall chips down a little bit more and a little bit more, we are going to see local spread," he said.
"You just have to look to Western and Eastern Europe, places that had high immunity, high vaccines rates, that are seeing resurgences and measles that is actually transmitting locally even throughout the year."
Clarifications
- An earlier version of this story included a quote from Dr. Zain Chagla suggesting there was no evidence of community transmission of measles. That was accurate at the time of the interview. The story has been updated to reflect reports of possible cases of person-to-person spread.Mar 04, 2024 12:47 PM EST
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