Those who are most at risk will receive their second doses first, including seniors and Elders, Indigenous people, and those identified as clinically extremely vulnerable. About 400,000 people over age 70, or who are clinically extremely vulnerable, will receive invitations to book their second dose Thursday.
The National Advisory Committee on Immunization has updated its guidance to say that it’s safe to have a second dose that is the same type of vaccine, although not necessarily the same manufacturer. For example, if someone received a Moderna vaccine as their first dose, they may receive a Pfizer vaccine as their second dose, since both are messenger RNA (mRNA) vaccines.