Dr. Theresa Tam says the Delta variant of the virus that causes COVID-19 might mean the country has to up its vaccine game again.Federal modelling done in April and May suggested that if 75 per cent of eligible Canadians — those 12 years old and above — had at least one dose of a COVID-19 vaccine, and 20 per cent had two, provinces could safely begin easing restrictions on public movement without overwhelming hospitals again.When 75 per cent of eligible people are fully vaccinated, the modelling suggested personal measures like physical distancing and wearing masks could also begin to loosen.