Canada Has Officially Decided That It's Safe To Mix & Match Some COVID-19 Vaccines

Canada is updating its guidelines when it comes to mixing and matching COVID-19 vaccines, according to the country's leading public health officials.

On Tuesday, June 1, Chief Public Health Officer Dr. Theresa Tam and Deputy Chief Public Health Officer Dr. Howard Njoo confirmed that Canadians will be able to combine AstraZeneca, Pfizer-BioNTech or Moderna COVID-19 vaccine doses interchangeably in certain situations.

"In short, the interchangeability of vaccines means you could receive one vaccine product for your first dose and safely receive a different vaccine product for your second dose to complete your two-dose vaccine series," Dr. Tam explained.

The top doctor said Canadians who received an mRNA vaccine as their first dose should be offered the same vaccine product as their second dose. However, she said that in circumstances where this is not available or possible, the other approved mRNA vaccines are interchangeable.

Canadians who received a first dose of the AstraZeneca COVID-19 vaccine could be offered the same for their second dose or one of the mRNA vaccines.

Canada's National Advisory Committee on Immunization (NACI) has formally updated its guidelines, with new recommendations shared on the same day.

This comes after several Canadian provinces paused the use of AstraZeneca vaccines in Canada, following reports of rare blood clots and supply issues.

Previously, the committee said both doses should be the same COVID-19 vaccine product, meaning those who received an AstraZeneca first dose should receive the same for their second dose.

However, new research from the U.K., Germany and Spain has found that mixing and matching is both safe and effective.