Nearly 1,000 cases of a new sub-variant of Omicron COVID-19, called ‘BA.2.20’, have been detected in Ontario since mid-February, and it may have a slight growth advantage over the current line dominating the province.
Ontario Public Health says the new sub-option “is increasingly circulating mainly in Ontario and some U.S. states,” according to a report quietly released Monday.
A second major iteration of the Omicron variant, known as BA.2, is now dominating the province as the sixth wave of the pandemic subsides.
This new Ontario-specific subvariant has two mutations that make it different from BA.2, but the exact effect of the mutations is not yet known.
“The effects of these mutations on transmission, risk of serious illness, reinfection and breakthrough infection are currently unknown,” Ontario public health researchers wrote in a report earlier this week.
To date, about 996 cases of the sub-variant have been detected in the province.
An analysis of the cases of BA.2.20 identified so far suggests that there may be up to a 24 per cent growth advantage associated with the new subvariant over the dominant strain BA.2, but they assess this finding with a low degree of confidence.
Epidemiologists say the first Ontario case of this new subvariant was discovered in London, Ontario. on February 14, 2022
It received the official designation of the Pango line, which certifies it as unique back in April.
His earliest known example worldwide was also found somewhere in Canada in January.
The proportion of BA.2.20 cases increased in Ontario from less than one percent in early March to six to seven percent by mid to late April.
It is most common in Toronto, the wider GTHA, and London, mostly among young people between the ages of 20 and 39.
Eighty-five percent of known cases involve people who have received two or three doses of the COVID-19 vaccine.
Only 19 of Ontario’s 996 public health examples known to date have been found through border tests on arriving air and land passengers.
Three percent (30) of the cases identified so far require hospitalization, followed by approximately the observed levels of Omicron hospitalization since March.
No deaths due to BA.2.20 infection were observed until 20 April.
As of April, ten percent of all Ontario-confirmed cases of COVID-19 were targeted for overall genomic sequencing, which is less than 50 percent of all cases detected in March.
New sub-variants of COVID-19 strains are appearing regularly around the world, but this is the first time such a sub-variant has appeared so highly concentrated in Ontario.
Public health agencies use a lengthy laboratory process known as complete genomic sequencing to map the unique characteristics of the coronavirus as it develops to identify the level of risk posed by the changes.
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