HALIFAX — People who received a single dose of the Oxford-AstraZeneca vaccine should opt for one of the other vaccines as a booster shot, Nova Scotia's chief medical officer of health said Monday.
Dr. Robert Strang cited research indicating a second dose of either the Moderna or Pfizer-BioNTech vaccines provides a better immune response than two doses of AstraZeneca.
"We are just revising our informed consent process," Strang told reporters. "With the latest evidence … I felt there was enough for me to give a clear recommendation to Nova Scotians."
Strang, however, said people will have a choice of which vaccine to take. "Ultimately, people can still choose AstraZeneca if that's their preference or are unable to use an mRNA vaccine," he said.
The Pfizer and Moderna vaccines are messenger RNA or mRNA vaccines, which teach the body's cells how to produce a protein that triggers an immune response. The AstraZeneca vaccine is known as a viral vector vaccine, which uses a modified version of another virus to teach the body's cells to produce the protein.
Nova Scotia has about 2,000 doses of AstraZeneca that are set to expire at the end of the month. The province has said about 58,000 Nova Scotians have received a first dose of AstraZeneca.
Strang said it's likely the remaining vaccine will expire if it's not used by Nova Scotians. "We have already talked to the federal government — there is no process for us to return that vaccine once it's out on the front lines," he said.
Slightly more than 61 per cent of Nova Scotians have received at least one shot of a COVID-19 vaccine. As of Sunday, 637,911 doses had been administered, with 44,567 people having received a booster shot.
Meanwhile, health officials reported 14 new cases of COVID-19 on Monday. Eleven new cases were identified in the Halifax area, two in the province's eastern zone and one in the western zone.
Officials said two of the Halifax-area cases are connected to schools in Dartmouth — Graham Creighton Junior High and the Bedford and Forsyth Education Centres campus. Both cases involve close contacts of previously reported infections.
Schools were opened across the province last week as part of the first phase of the government's five-step reopening plan. Strang said he wasn't surprised and "fully expected" the new school cases given there is still virus activity in the Halifax area. He said that similar to previous school-based cases, people were exposed in the community, adding that there are no signs of transmission in either school.
"The benefits for children and youth learning in person at school with their peers far outweighs the very low risk of our current COVID activity," he said.
Nova Scotia has 182 active reported cases of COVID-19 and 22 people in hospital with the disease, including seven in intensive care.
Premier Iain Rankin said the steadily falling case numbers should allow the province to enter Phase 2 of its reopening on June 16.
This report by The Canadian Press was first published June 7, 2021.
Keith Doucette, The Canadian Press
