Some New Brunswickers will be rolling up their sleeves for the second time this weekend to receive the second dose of Pfizer’s COVID-19 vaccine, the timing of which experts say could impact its effectiveness.
Linda Shannon of Sackville said she is thrilled to be among people scheduled to receive their second dose the vaccine on Saturday in Miramichi.
“I am very happy to be getting my second dose tomorrow at 4:40, so that will be exactly 21 days to the hour, basically,” said Shannon.
Unlike neighbouring Quebec now holding back on administering some if its second doses, New Brunswick is getting needles into people’s arm within Pfizer’s recommended window, said Shannon.
“My understanding is that the studies were done based on 21 days,” she said.
Pfizer says it can only support the usage of the vaccine according to the label indication agreed upon with Health Canada and the data from their vaccine trial, “which is to administer the two vaccine doses 21 days apart,” said Pfizer spokesperson Christina Antoniou.
“There are no data to demonstrate that protection after the first dose is sustained after 21 days.”
According to Dr. Jorg Fritz, an immunologist and associate professor of microbiology and immunology at McGill University, New Brunswick health authorities should be sticking to that strict timeline between doses as the vaccine rollout is expanded in the coming months.
“If we wait too long there is a likelihood based on our experience with other vaccines that it would be less effective so we should stick as possible to the recommended schedule,” said Fritz.
On Friday, New Brunswick’s chief medical officer, Dr. Jennifer Russell, said the province has been consulting with the Health Agency of Canada and Health Canada and has no plan to alter the recommended dosing schedule.
“We didn’t really have any intention of changing the interval unless there was a need for alignment in terms of the way we would line it up or if there was some unforeseen circumstance around transportation, etc.,” said Russell.