May 20, 2021
By Jane Brown
Canadian researchers have launched a clinical study that could have a direct bearing on the Canadians who received a first dose of the AstraZeneca COVID-19 vaccine, and live in provinces that have stopped offering it because of it’s link to a very rare type of blood clot.
The federally funded study will examine the effects of mixing doses of COVID-19 vaccines, primarily with AstraZeneca as a first dose and an mRNA vaccine as a second dose.
A published report also says if the recruitment of 1300 participants proceeds quickly, the research could inform those involved in the vaccine rollout, along with the National Advisory Committee on Immunization, who are looking for data that shows whether a mix and match scenario is acceptable.
Ontario Health Minister Christine Elliott told the legislature Wednesday they are awaiting more research on options for people who got the AstraZeneca vaccine first before announcing a decision on second doses.
“Either they will receive the second dose of AstraZeneca, and there are indications coming from the U.K., and there are indications coming from the U.K. that the VITT (rare blood clot) link is much much less (one in a million) than with the first dose, and in the event that we don’t proceed with those AstraZeneca doses, also from the U.K., there is evidence it can be combined with an mRNA dose, either Pfizer or Moderna.”
Elliott also confirmed that the 45,000 AstraZeneca doses in reserve will not go to waste despite their May 31st expiry date.