COVID-19 vaccines are administered at a mass vaccination clinic run by Switch Health in Mississauga, Ont., Dec. 24, 2021.Chris Young/The Canadian Press
Moderna will be the main supplier of COVID-19 vaccine doses for the country’s booster campaigns as governments across the country urge eligible Canadians to get their third shot as soon as possible in the face of a surging fifth wave.
The federal government says it has secured enough COVID-19 booster shots for everyone eligible to get their doses at the appropriate interval. However, with deliveries of the Pfizer doses front-loaded to earlier this year, and those from Moderna back-loaded to later in 2021, Canadians will not necessarily get a choice between vaccines when they stick their arms out for the latest jab.
That means that many Canadians who received Pfizer doses for their first and second shots could get their boost against the new Omicron variant from a Moderna shot. The Public Health Agency of Canada (PHAC) said it recognizes that people may prefer the same vaccine brand for all shots, but underscored that mixing mRNA vaccines is safe and protects against COVID-19.
“NACI has recommended that mix-and-matching, or the heterologous schedule, is protective, and for those Canadians who received a viral vector for their primary series, preferred,” PHAC spokesperson Mark Johnson said in a statement.
In June, the National Advisory Committee on Immunization (NACI) said it expected that mixing different vaccines “will lead to a robust immune response.”
Canada received about half as many Pfizer doses than Moderna doses in the last quarter of 2021, and will get nearly double the number of Moderna doses in January compared to Pfizer shots. Additionally, because people in most age groups who get a Moderna shot for their booster only require a half dose, the deliveries from Moderna will cover many more people than those from Pfizer. A full dose of Moderna is recommended for boosters for adults who are 70 and older and people who are severely immunocompromised.
“Over 8.6 million full doses of Moderna Spikevax have been imported in the last quarter of 2021, sufficient vaccine for up to 17.3 million boosters. An additional 9.3 million full doses of Moderna Spikevax are expected in January,” Mr. Johnson said.
Canada has signed additional agreements with both Pfizer and Moderna for delivery of their mRNA COVID-19 vaccines in 2022, 2023 and 2024. But while Canada has already received its doses from its original contract from Pfizer, about half are still expected from Moderna.
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Last week, Mylène Drouin, Montreal’s director of public health, said the city has more Moderna than Pfizer on hand and sought to reassure Quebeckers that mixing brands is safe – and especially important given the need for booster shots.
“Switching doses from Pfizer to Moderna is secure – it gives protection against Omicron,” Dr. Drouin said. “Moderna is a good vaccine and we do not see in the literature that it has more side effects.”
Also putting pressure on Pfizer supply is the NACI recommendation that the Pfizer shot should preferably be given to those aged 12 to 29 for their primary series of shots (first two doses), and for the third shot for people between 18 and 29. That advice was given because of the lower risk of myocarditis or pericarditis with the Pfizer shot.
“In people over 30 years of age, either mRNA vaccine can be used for the booster,” the independent vaccine advisory group said.
Given that advice, Mr. Johnson said PHAC is asking provinces to “prudently plan, reserve and monitor their supply of Pfizer to ensure access for this age group.”
“Canada has secured sufficient doses of Pfizer vaccine to meet needs based on NACI’s preferential recommendations” that Pfizer be used for younger age groups, Mr. Johnson said. “Canada also has ample supply of Moderna Spikevax, which has been proven to be safe and highly effective and is readily available for the 30+ age groups.”
In Ontario, Alexandra Hilkene, spokesperson for Health Minister Christine Elliott, said the province is advising public-health units to ensure enough supply of Pfizer for younger people before offering the option between Pfizer and Moderna for older age groups.
“Given historical uptake of Pfizer, some public-health units are experiencing limited supply,” Ms. Hilkene said.
The province has asked Ottawa for four million Pfizer doses in January, but is unlikely to get that much as the entire country is only receiving five million doses of Pfizer in January. In its statement to The Globe, the Public Health Agency of Canada said the doses are being divided up on a per capita basis and the provinces and territories have already been advised about the forecasted supply levels.
“We will be working closely with the federal government to understand incoming vaccine supply for January to March, but we have received assurances that there will be enough vaccines for all Ontarians as we continue to rapidly expand capacity and eligibility for booster doses,” Ms. Hilkene said.
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