Nurses close the curtains of a patients room in the COVID-19 Intensive Care Unit at Surrey Memorial Hospital in Surrey, B.C., Friday, June 4, 2021. THE CANADIAN PRESS/Jonathan Hayward

Nurses close the curtains of a patients room in the COVID-19 Intensive Care Unit at Surrey Memorial Hospital in Surrey, B.C., Friday, June 4, 2021. THE CANADIAN PRESS/Jonathan Hayward

Rate of more contagious delta COVID-19 variant increasing in B.C. with 500 cases so far

Independent modelling group says variant poses a ‘serious risk’

As more and more British Columbians receive their COVID jabs, a variant could make the race between immunizations and the virus more heated.

The delta variant, scientifically dubbed B.1.617, was first reported by the province on April 22. At the time, health officials said there were 42 cases in the province. On Monday (June 7), Dr. Réka Gustafson, deputy provincial health officer and lead of the vaccine rollout, said the province had recorded about 500 cases – a figure she called “relatively uncommon.” Exact variant counts fall behind actual case counts due to the time it takes to do full genome sequencing.

The Delta variant has caused trouble both in Canada and abroad. In India, where it appears to have originated, it contributed to a month of daily death counts in the 3,000 and 4,000 range. In the United Kingdom, public health officials have said it’s 40 per cent more contagious and in Ontario, it’s on track to become the dominant variant, beating out alpha variant (B.1.117).

Speaking Monday, Gustafson was unable to provide information on where the delta variant is spreading in B.C. but said that it “has had an increase in the rates over the last several weeks and we will continue to monitor it.”

However, an independent modelling group made up of scientists from three major B.C. universities is concerned. In a video released June 2, University of B.C. associate professor of mathematics Eric Cytrynbaum said there was evidence that the delta variant was more resistant to the Pfizer vaccine, dropping from about 50 per cent for the alpha (B.1.117) variant after dose one to 33 per cent for the delta one.

The modelling group stated that if the delta variant remains contained, the May 25 Step 1 reopening is expected to lead to a “moderate” increase in cases, which will drop as more people are vaccinated.

“We should aim for more than 70 per cent vaccination of 18+ (~60% of all ages) in order to allow more reopening safely, especially in light of newly emerging VOC, like (delta variant) B.1.617.2,” the modelling group said.

“Delta poses a serious risk with with a potential five to 10 per cent per day increase in spread (over alpha),” Cytrynbaum said.

At the time the video was posted, 71.1 per cent of British Columbian adults had received one dose of a COVID-19 vaccine. As of Tuesday, one week after, 74.2 per cent of adults have received at least one dose.

The B.C. Centre for Disease Control said that the first case of the delta B.1.617.2 variant was detected between March 21 and March 28 in the province. the BCCDC said that at the time, it was designated as B.1.617, which was split into three “sub lineages,” including delta B.1.617.2.

The BCCDC said the delta variant’s introduction into the province “appears to be travel related” and came in through multiple travellers, with the variant currently being found mostly in Fraser Health and Vancouver Coastal Health.

READ MORE: Tam urges 2nd COVID vaccine dose as Delta variant emerges ‘essentially across Canada’


@katslepian

katya.slepian@bpdigital.ca

Like us on Facebook and follow us on Twitter.

Coronavirus