It is only April, and 2025 is already emerging as the worst year for measles, since the disease was declared eliminated in 1998 in Canada.
Ontario remains the epicenter of propagation. Ontario public health reports 1,018 confirmed and probable cases of measles so far this year. The vast majority of those infected were not completely immunized. Six unaccoured children and adolescents have been hospitalized with the virus.
In Alberta too, the virus is spreading. The province reports 129 cases as of April 24, in each area of the province. In that province, most patients are not completely vaccinated. Nine people have been hospitalized.
Measles is one of the most contagious diseases known by man. Symptoms can include a fever, cough and liquid nose, as well as a stained red eruption. In severe cases, measles can cause complications such as inflammation of the brain, pneumonia and death.
As the virus spreads, there are some common questions about measles immunity.
Can measles immunity decrease?
Two doses of the measles, paperras and rubella (MMR) or measles, paper, rubella and chickenpox (MMRV) Almost 100 percent long -term effectiveness.
Even so, immunologist Dawn Bowdish He says he has been presenting questions about the diminishing immunity of those concerned that they are not perfectly protected from the virus.
“Most of us who were born after 1970 have never found measles; we have only been vaccinated. We know that a small percentage of people in that scenario will have some decrease in immunity,” he said.
That could mean that some innovative infections can occur among those who received two doses of a measles vaccine.
It is a game of numbers: the more measles it is spreading, the more likely an innovative infection occurs, says Dr. Lynora Saxinger, a specialist in infectious diseases at the University of Alberta.
“People who have had two doses are substantially protected, but not bulletproof.”
Even when those who are totally vaccinated receive an infection, are less likely to suffer the most serious consequences, says Dr. Dale Kalina, medical director of Brant Community Healthcare System in Brantford, Ontario, an area that has had measles cases since January.
“The reality is [those who’ve received two shots] Are not the people who would worry about an outbreak, from a propagation perspective, or from a perspective of complications or a need for hospitalization, “he said?
How can I verify if I am protected against measles?
There is a blood test that seeks measles antibodies. If obtaining it or not a conversation that people need to have with their family doctors, says Bowdish.
Health workers or those who work with vulnerable people are often evaluated by antibodies, as are some pregnant women. Bowdish says that he would like to see that this is the standard of attention throughout the country, because measles used to be an important cause of lost pregnancies, dead dead and birth defects in areas of the world with irregular vaccination rates.
“As we advance to an era in which we have much more measles, personally I support me a lot in pregnant women or people who plan to start a family, receiving this test.”
Bcoming cases in BC are still low, with only five confirmed cases, all related to trips. But elsewhere, the numbers are exploiting. Experts warn about greater spread due to low vaccination rates. The CBC medical columnist, Dr. Melissa Lem, says she has been presenting questions from worried parents. She says that school -age children are particularly vulnerable, and the virus can leave lasting damage to the lungs and the immune system and even cause brain damage.
However, those who are not sure if they have been completely vaccinated are better obtaining another dose, instead of doing blood analysis, says Bowdish.
“If you can’t find your vaccination status, if you come from parts of the world that do not have childhood measles [vaccinations]If you are worried that your parents have not vaccinated as a child, our recommendation is to vaccinate, “he said.
Those born before 1970 are generally believed to be protected, says Bowdish, because they were exposed to measles when they were children.
Do I need a third dose of the measles vaccine?
Canadian public health authorities do not recommend a third dose of the MMR vaccine for the general public, although it is generally safe. This is because it would not make sense to prioritize the limited time and the public health resources that we have to give a third dose at this time, says Bowdish.
There are some exceptions, such as those taking immunosuppressive medications or cancer treatments, says Bowdish. But those decisions should be made after a conversation between the patient and his doctor.
Saxinger agrees.
“Make sure … people who are not vaccinated are vaccinated first is a kind of clear priority. There may be a time when we would begin to look at the use of additional doses for more people, but I don’t know if it’s enough now.”
