Canada recommends mixing, matching of COVID-19 vaccines- AstraZeneca, Pfizer, Moderna

Based on the study from UK and Spain, Canada, on Tuesday recommended mixing and matching second doses of COVID-19 vaccines. The country is using AstraZeneca, Pfizer, and Moderna and has suggested citizens to combine jabs interchangeably in certain situations. The National Advisory Committee on Immunization (NACI) has extended its support to the decision and updated its guidance to provinces and territories on mixing and matching. 

Canada's Chief Public Health Officer Dr. Theresa Tam also gave a green signal to the process while adding that this is nothing new. 

"This is not a new concept, so having a multi-dose series in terms of vaccines given by manufacturers is something that public health has used over time for many other vaccines. When vaccines programs and supplies change this is not an unusual thing to do," said Dr. Theresa Tam to CBC News.

Dr. Theresa Tam further cited the example of mixing shots for influenza and Hepatitis proving this phenomenon is not new.

The NACI guidance comes from research conducted in UK, Spain that said mixing and matching shots are safe and effective. The study further recommended first shot of the AstraZeneca vaccine can be followed by either Moderna or Pfizer. Following the recommendations, Canadians have also been advised to take either of the two shots as a second dose after taking first dose of Moderna or Pfizer. 

Details of the research

The scientific analysis shows that safety is assured as both vaccines- Moderna or Pfizer uses similar mRNA technology. In case if same first dose is unavailable or unknown then either of the two shots can be taken during the second jab. The officials from the Public Health Agency of Canada confirmed the update in the guidelines during Tuesday's news conference, reported CBC News. 

Currently no data on interchangeability

On contrary, NACI's updated recommendations have clarified that "no data currently exist on the interchangeability of COVID-19 mRNA vaccines," however Canada's Chief Public Health Officer added that there are 'ongoing studies' on the enhanced effects which will be published. She also highlighted that the decision was made considering similar makeup of the vaccines, which both target the spike protein of the coronavirus. 

The updated guidelines come at a time when issues with the supply of AstraZeneca and a rare but serious type of blood clot were witnessed, enlightened NACI. The new suggestions are expected to have major changes in the vaccine drive of Canada as major changes have been made from the previous rules. 

Canada COVID-19 vaccine drive

According to the latest available federal government data, till May 22, over 13 million Canadians have received at least one dose of the Pfizer vaccine in Canada, in contrast to over 3.5 million of the Moderna vaccine and more than 2.1 million of the AstraZeneca vaccine. 

(With ANI inputs)