As it stands currently, the Moderna vaccine requires two doses administered about 28 days apart. The Pfizer-BioNTech vaccine, the only other COVID-19 vaccine currently approved for use by Health Canada, also involves two doses, taken some three weeks apart. WATCH | Retired general Rick Hillier asks if the Moderna vaccine could be a single dose:Hillier asks: Can Moderna vaccine work with just one shot? News Video 1:14 The head of Ontario's vaccine distribution task force, retired general Rick Hillier, wants Health Canada to see if a single dose of the Moderna COVID-19 vaccine offers enough protection to avoid a second shot. And speaking to CBC News on Dec. 23, the general manager of Moderna Canada rejected the idea.

Source: CBC News December 29, 2020 14:00 UTC