Millions of Ontarians who are planning to take advantage of the more than 73 million doses of diphtheria, tetanus and pertussis (DTaP) vaccine to help prevent the seasonal measles and pertussis, or whooping cough, will need to get vaccinated against the Pertussis in early November. Every province except Quebec had its normal program to protect against measles and pertussis last spring and fall, so in some regions people didn’t get their third dose of DTaP until late October, and were left unprotected from a serious and sometimes fatal infection. The reasons why the third dose of vaccine was late are complex, but usually due to a vaccine-to-toxin mismatch between a vaccine and the diphtheria vaccine.
So Ontarians are back to getting their third dose of DTaP. While governments are working to ramp up capacity to catch up on the vaccine schedule and treat those who have already been exposed to the disease, some vaccinations won’t be available until March 2020.