Getting not only first doses but also second doses into arms as quickly as possible after the four-week mark (which experts agree is the minimum interval for effectiveness) is vital to stopping that from happening, Bogoch said. "We know that two doses of AstraZeneca at a 12-week interval provides a better immune response than over a shorter interval," the ministry said. But there's no evidence that's the case when people choose an mRNA vaccine instead of AstraZeneca as their second dose, she said. "What needs to be discussed at the Ontario level is this gain in earlier protection for more people when they get their second dose." "What we all want is to be fully vaccinated before this delta variant starts to get transmitted very actively in the community."

Source: CBC News June 10, 2021 23:03 UTC