Canada’s national panel of vaccine experts says the second COVID−19 vaccine dose can be delayed briefly in a bid to get more people a first dose faster.
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 vaccine supplies are slow to trickle in, they say delaying the second dose up to six weeks, instead of three or four, could more quickly get at least some protection against COVID−19 to more people.
Canada is getting enough vaccine doses to vaccinate the vast majority of Canadians by the fall but the bulk of that won’t happen until later in the spring and summer and provinces are warning they’re going to run out of doses.
Almost 550,000 doses have now arrived in Canada and about 71% of them injected, with another 380,000 doses scheduled to arrive by the end of the week.
Clinical trials on the Pfizer−BioNTech and Moderna vaccines both 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.
The news comes as seven residents of a Montreal long−term care centre who received a first dose of the Pfizer−BioNTech vaccine were confirmed to have contracted COVID−19.
Management at the Maimonides Geriatric Centre informed patients in a notice sent Tuesday, noting that residents were infected within the first 28 days of receiving their first of two vaccine doses.
Quebec has decided to delay administering second doses to patients and has instead chosen to give a first dose to as many people as possible.
Last week, a dozen Maimonides residents sued the province to obtain a second dose within 21 days of their first dose — the time frame set by the vaccine manufacturer.
News of the COVID−19 infections at Maimonides doesn’t surprise Dr. Donald Vinh, microbiologist and infectious disease specialist at the McGill University Health Center.
He says it takes up to 14 days between a vaccination and the time when the body builds enough immunity to be protected against the novel coronavirus.