The National Advisory Panel for Immunization is recommending mRNA vaccines as the “preferred” choice for all Canadians, except in the case of allergies to any ingredients.
People who received AstraZeneca should also received an mRNA vaccine for their second dose whenever possible.
The new recommendation from NACI was made due to the “increasing availability” of the Pfizer and Moderna mRNA vaccines, as well as “emerging evidence suggesting better immune responses when a first dose of the AstraZeneca vaccine is followed by a second dose of the Pfizer-BioNTech mRNA vaccine.”
AstraZeneca also carries the risk of Vaccine-Induced Immune Thrombotic Thrombocytopenia (VITT), although health officials have repeatedly said the risk is very, very low. However, the condition has not been linked to any mRNA vaccines.
However, individuals who received two doses of AstraZeneca “can rest assured that the vaccine provides good protection against infection and very good protection against severe disease and hospitalization,” according to NACI.
Chief public health officer Dr. Theresa Tam said that people should feel “very comfortable” with two doses of AstraZeneca and that NACI has been “extremely transparent” in making its recommendations as the science has changed.
“I understand that this is difficult for many,” Tam said during the Thursday (June 17) press conference where the new recommendation was made.
To AstraZeneca recipients, she said “you have been provided with good protection against infection. Whichever vaccine you get, its that second dose that’s very important.”
The recommendations made Thursday appear to be the final evolution of NACI’s vaccination advice. At first, when supplies were low, Canadians were largely told to take the first vaccine offered, regardless of what it was. On May 3, Canadians were told that they should get an mRNA vaccine unless they felt like it was too risky to wait given their local area’s positivity rate and their personal circumstances.
More to come.