Canadian measles outbreak continues unabated

A measles outbreak in Canada continues unabated in both the immunized and unimmunized population, raising questions about the effectiveness of the nation’s vaccines.

Quebec is in the middle of the largest outbreak of measles reported in the Americas in the last decade, despite the implementation of two mass vaccination campaigns in the province in 1996, according to

In 1996, Quebec launched a campaign to administer a second dose of the measles vaccine to children between the ages of 18 months to 16 years. A second campaign was implemented to introduce a two dose schedule for young children between 12 to 18 months.

The campaigns were thought to have increased the coverage rate to approximately 89 percent. The current measles outbreak, however, shows no sign of slowing.

“While this still ongoing outbreak feeds largely on unvaccinated individuals, the high proportion of cases who received two doses raises concerns on vaccine effectiveness,” Dr. Philippe Belanger, a Quebec public health official, said, reports. “However, the take-home message is still to get vaccinated.”

Overall, 66 percent of the measles cases in the outbreak have occurred in unvaccinated individuals, 24 percent of the cases had written proof that they received the vaccination and 10 percent reported being vaccinated without possessing written proof.