Russia Some international experts have also questioned the speed at which Russia approved its vaccine.
"Normally you need a large number of people to be tested before you approve a vaccine," said Peter Kremsner of the University Hospital in Tuebingen, Germany, currently testing CureVac's coronavirus vaccine in clinical trials.
"In that respect, I think it's reckless to do that [approve it] if lots of people haven't already been tested."
Dr. Zain Chagla, an infectious disease specialist at St. Josephs' Health Centre in Hamilton, told CBC News that's because many side-effects only show up in a small percentage of the population. For example, you'd have to test 200 volunteers in order to see a major side-effect that affects 0.5 per cent of people who are vaccinated.
"It's very dangerous to scale this up to an entire population without doing those trials,"