When the first doses of COVID-19 vaccines finally arrive in Canada, the country will need to grapple with a series of difficult questions that ethicists fear we haven’t spent enough time answering. For example, which groups should get vaccinated after those most vulnerable? How long will it take for everyone to get their shot? And what happens if a person refuses to get vaccinated? The clock is ticking to address those questions. Pfizer’s vaccine candidate, which is more than 90-per-cent effective according to the company’s preliminary results, could be approved for use in Canada before Christmas, according to Health Canada’s chief medical adviser.