During a COVID-19 briefing on Tuesday, the SHA said there about 20,000 AstraZeneca shots available for second doses.
“We’re not using AstraZeneca as a first dose strategy anymore, so we’re not stockpiling AstraZeneca doses in the province to give us first doses,” said SHA CEO Scott Livingstone.
“We’re using it as a second dose strategy moving forward.”
The SHA said AstraZeneca is currently only available as second doses for individuals who received the AstraZeneca vaccine for their first dose and who are over the age of 85.
Cancer patients, solid organ transplant patients or patients receiving treatment with Rituximab and Ocrelizumab who received AstraZeneca as a first dose are also eligible to receive it for their second dose.
The SHA said those patients will have received a letter and will be contacted for an appointment.
The health authority said it will provide further guidance on the administration of AstraZeneca second doses for the general population prior to the recommended twelve-week interval between doses.
Dr. Saqib Shahab, the province’s chief medical health officer, said those who received AstraZeneca in March will be eligible for a second shot within the next few weeks.
“Waiting for the 12 weeks is really important for long-term protection because… the aim of two doses is not just looking at the spring and the summer. We want to see a COVID-free fall,” he said.
“That’s why getting AstraZeneca at the optimum 12 weeks would be ideal and preferable.”
Shahab understands people may be concerned about receiving a second dose of AstraZeneca over reports of vaccine-induced thrombocytopenia thrombosis.
He said the rate in Canada is around one in 50,000 with first doses.
“We know that the second doses, the incidence rate may be lower,” he said. “So there’s good evidence now to support second doses with AstraZeneca.”
Shahab added that they are still waiting for guidance on mixing the first and second doses between AstraZeneca and Pfizer.
“We are waiting for some antibody data to see if a second dose of Pfizer does mount an immune response as good as a second dose AstraZeneca,” he said.
Anyone who received their first dose on March 15 is expected to be eligible for their second shot by the end of May.
Those who had their first jab on March 22 should be in line for their second by June 7.
— Kyle Benning contributed to this story.