Canada’s national panel of vaccine experts says the second COVID-19 vaccine dose can be delayed briefly in order to quickly get first doses to more people.
The National Advisory Committee on Immunization says every effort should be made to follow the 21-day and 28-day dosing schedules recommended for the two vaccines approved in Canada to date.
But as the pandemic heats up, and as vaccine supplies trickle in slowly, the panel also says that delaying the second dose for up to six weeks — instead of three or four — could quickly give more people at least some protection against COVID-19.
Canada is getting enough vaccine doses to vaccinate the vast majority of Canadians by the fall — but most of those doses won’t arrive until later in the spring and summer and provinces are warning they’re going to run out.
Almost 550,000 doses have now arrived in Canada and about 71 per cent of them have been injected. Another 380,000 doses are scheduled to arrive by the end of the week.
Clinical trials for the Pfizer-BioNTech and Moderna vaccines showed the first dose provided some protection against serious illness from COVID-19. But the majority of patients in both trials received a second dose on schedule, leaving very limited data on how long the protection from the first dose lasts.