On Nov. 15, 2021, Moderna confirmed that Health Canada authorized the use of a booster dose of the Moderna COVID-19 vaccine (SPIKEVAX™) at the 50 µg dose for individuals aged 18 and older administered at least six months after completion of the primary series.

Health Canada based this authorization on the totality of scientific evidence shared by the company, including a data analysis from the Phase 2 clinical study of mRNA-1273, which was amended to offer a booster dose of mRNA-1273 at the 50 ﾵg dose level to interested participants 6-8 months following their second dose.