Following series of warning by medical experts concerning the strange and harmful side effects associated with the AstraZeneca vaccine, Canadian health officials are now reviewing the research on mixing various COVID-19 shots.
Some health experts believe that administering two doses of different products could boost a person’s immune response beyond what can be achieved by giving the same shot twice.
The National Advisory Committee on Immunization (NACI) has been said to have caused some confusion earlier this month when it said the viral vector shot from AstraZeneca is not the “preferred” product given its associated risk of vaccine-induced immune thrombotic thrombocytopenia (VITT) — a condition that causes blood clots. That warning came out after hundreds of thousands of Canadians had received the AstraZeneca vaccine already.
According to the ontario science table estimates of the frequency of VITT in individuals who have received the AstraZeneca vaccine now range from 1 case in 26,000 to 1 case in 127,000 doses administered.
The risk of developing this side effect, combined with an uncertain delivery schedule, has prompted some provinces to consider pausing AstraZeneca vaccinations altogether.
Dr. Brent Roussin, Manitoba’s chief provincial public health officer, said Sunday a temporary suspension “has been discussed at many levels, and certainly discussed at our provincial program right now.”
Christine Elliott, Ontario’s health minister, said Monday that recipients of the AstraZeneca vaccine may receive a different shot for their second dose.
While the AstraZeneca product has been deemed safe and effective repeatedly by Health Canada regulators, some people who already have received that vaccine are now looking at their options.