B.C. experts urge caution during reopening, warn of delta variant 'wild card'

Vancouver -

A group of independent B.C. scientists and data researchers is urging the province to take a slow and cautionary approach before reopening further due to a variant that was growing even during the “circuit breaker” restrictions.

In its latest bi-monthly report, the B.C. COVID-19 Modelling Group hopes its latest analysis encourages decision-makers to slow down and scrutinize the behaviour of the B.1.617 variant, now known as the "delta variant."

The scientists are also warning public health officials to fully vaccinate as many people as quickly possible to avoid the rise of the delta variant, which has seen a concerning resurgence in cases in the United Kingdom and is threatening that country's reopening.

"The good news is B.C. continues to see the case numbers decline, which his fantastic, but the wild card is B.1.617.2,” said co-author and UBC biomathematics professor Sally Otto. “That variant is spreading in India and really wreaking havoc there."

The B.1.617 variant, discovered in India and newly termed the “delta variant” by the World Health Organization, is widely believed to be twice as likely to spread compared to the P.1 (Brazilian origin) and B.1.1.7 (U.K. origin) variants, which were already more contagious than the original strain of COVID-19.

“With currently dominant strains (P.1 and B.1.1.7), cases are projected to increase briefly and then turn around later in June, as vaccination levels rise,” write the B.C. report’s authors. “Vaccine effectiveness with B.1.617.2 with dosing schedule used in B.C. is unclear. Current level of community spread in B.C. of B.1.617.2 is uncertain.”

Otto says that their group isn’t getting enough information from the B.C. Centre for Disease Control to know for certain how much of the .2 subset is circulating, versus the less-worrisome .1 and .3 subbranches of the variant.

“What we were also seeing is before we even reopened, before Step 1, that 617 was increasing in numbers in British Columbia, so it's looking to be ramping up and of course with reopening that would be even worse," she explained.

“I hope that this is yet another incentive for people that've been delaying or unsure about whether they should get vaccinated, because we will only be able to safely open up as these variants appear around the world, we'll only have insurance against them if a very large fraction of our population is vaccinated -- it just makes a big buffer, it makes it harder for the disease to spread from person to person."

On Wednesday, the BCCDC’s latest data showed a sharp increase in the delta variant up to its most recent analysis on May 9.

Two days earlier, the provincial health officer revealed that B.C. labs will once again start scrutinizing each positive COVID-19 sample, rather than the surveillance spot-checking they’d shifted to at the height of the third wave. It appears that’s due in part to the growth of the delta variant, which is about twice as contagious as B.1.1.7 and P.1.

“This is going to be more and more important as our numbers continue to go down and as people start to get more mobile and travel more so that we can detect if a new strain that has any characteristics, like being more transmissible or seeming to evade vaccine, gets introduced into the province," said Dr. Bonnie Henry on Monday.

She also pointed out that vaccination rates alone are not a guarantee for the next steps in B.C.’s reopening, and if infections stay high or grow they would reconsider when to relax more restrictinos. Mid-June is when B.C. has tentatively scheduled reopening movie theatres and fitness classes, allowing intraprovincial travel and extending liquor service hours.

Newly-released data from the Ministry of Health shows British Columbians 90 and older have the highest rates of first shots (91 per cent), with those between 70 and 90 years old between 86 and 90 per cent vaccinated. That’s the target Otto and her group are aiming for, but with second doses for maximum protection.

While rates are inching up and the eligible population 12 and older is at 68 per cent for first shots, Otto worries we won’t hit the targets and predicts clusters and outbreaks will continue as variants like delta tear through unprotected people.

"If a bunch of unvaccinated individuals are interacting with each other, that's going to lead to little epidemics until it's basically run its course through the community,” she said. “That’s we're going to see in groups of people, networks of people that don't want to get vaccinated."