Why were some isolation periods shortened for vaccinated people with COVID-19?
CBC
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British Columbia, Alberta, Saskatchewan, Manitoba, Ontario and New Brunswick have each announced shorter isolation periods for vaccinated individuals who test positive for COVID-19. The moves this week follow similar measures from the U.S. Centers for Disease Control and Prevention (CDC) to also shorten the isolation period in the United States.
Under the new guidelines, vaccinated people who test positive with COVID-19 will only be required to self-isolate for a minimum of five days following the date when their symptoms started or a positive test, instead of 10 days. Some health officials have suggested the new rules will be easier for people to follow and help alleviate worker shortages.
If, after five days, their symptoms have improved or subsided for at least 24 hours, they can end the isolation period. But they still should be masking and physical distancing.
And there are no changes to timelines for those who are unvaccinated.
Here's what you need to know about the new measures and the rationale behind the province's decisions.
At Friday's announcement, Alberta Chief Medical Officer of Health Dr. Deena Hinshaw said the move is "based on the evidence that those who are fully immunized shed virus for a shorter amount of time if they have a breakthrough infection."
Meanwhile in Ontario, Chief Medical Officer of Health Dr. Kieran Moore said Thursday that "90 per cent of your viral risk of transmission is already transpired by five days."
In Ontario, testing is now limited fto high-risk groups and the province wants people to self-isolate if they develop symptoms. Rapid tests are sold out in many places and on back-order among many retailers.
"We know from studies that if they have a rapid ascent, they will have a rapid descent in the amount of virus that they shed," Moore said.
He also said about 40 per cent of the spread actually happens in the two days before you develop symptoms — meaning you don't have the ability to protect people.
When asked about the change, Dr. Christopher Labos, a Montreal cardiologist with a degree in epidemiology, said it's clear that "the further you get from the start of the infection, the less infectious you are."
He said he can understand the rationale behind the move but whether it's a good idea remains to be seen.
"I'm not sure that in the current context, when we have very very rapidly spreading Omicron variant, that this would be the time to really shorten those requirements," said Labos.