Some urge COVID-19 vaccine certificates to require 3 doses as Ontario set for reopening
Global News
Dr. Gerald Evans, an infectious diseases physician and member of Ontario's science advisory table, said three doses should now be the definition of fully vaccinated.
Restaurants, gyms, cinemas and many other businesses in Ontario are set to open their doors once again on Monday to fully vaccinated patrons, but with COVID-19 levels likely just past a peak, some question if “fully vaccinated” should be redefined.
Businesses and facilities that were closed early this month in response to surging cases driven by the highly transmissible Omicron variant are being allowed to reopen with capacity limits and will need to operate under the vaccine certificate system. That means only allowing customers who show proof they’ve received two doses of a COVID-19 vaccine, which is currently considered fully vaccinated.
But experts have noted the vaccine certificate system was designed when the Delta variant was dominant and two doses offered robust protection against both severe illness and infection. Omicron, now responsible for nearly all COVID-19 activity in the province, is a different beast and the government has been urging residents to get a booster shot.
Dr. Gerald Evans, an infectious diseases physician and member of Ontario’s science advisory table, said three doses should now be the definition of fully vaccinated.
“I think there’s a lot of us who, understanding vaccine science and looking at how we deal with other kinds of vaccines for various infectious diseases, have really said this is probably a three-dose vaccine,” he said in a recent interview.
Ontario’s science table has pointed to evidence that two doses of an mRNA vaccine have about 35 per cent effectiveness against Omicron infection 14 weeks after receiving a second dose, while three doses can offer 75 per cent protection in the first month.
When it comes to preventing not just infection, but severe illness and death, that booster dose can be 90 per cent effective or more, said infectious diseases physician Dr. Andrew Morris.
“We know that for most people, after the second dose, because of the time since when they got the last dose, immunity has waned pretty substantially and so it’s not nearly as protective as it was,” he said.
