75% vaccination trigger too low, opening borders 'dangerous,' expert says

Jennifer Russell calls it New Brunswick's COVID-19 "sweet spot," but it could go sour very fast, according to some experts who've studied and praised the province's strict measures.

The chief medical officer of health was referring to easing of pandemic restrictions in tandem with rising vaccination rates to keep case numbers relatively low, like they've been through the pandemic.

"It's risky," says Malgorzata Gasperowicz, a biologist at the University of Calgary who studies cell behaviour and who publicly urged other provinces to match Atlantic Canada's strict lockdown measures last fall. "It's dangerous."

She says the trigger for the province's move to Phase 1 of reopening, 75 per cent of eligible New Brunswickers having a first dose of vaccine, is "totally not enough" given the rising number of COVID-19 Delta variant cases elsewhere in Canada.

Likewise, she says letting Canadians from outside the region with only one dose enter the province without self-isolating in Phase 2 jeopardizes the success so far.

"I wouldn't want to import Delta if I were in a clean region," she says.

University of Ottawa epidemiologist Dr. Raywat Deonandan isn't as worried, but says case numbers outside Atlantic Canada should be a major part of New Brunswick's criteria for reopening.

"What's missing there is: what's the rest of Canada doing?" he says.

"What's outside the bubble? How's the rest of Canada doing before we lower the drawbridge? Is the invading army still camped outside the castle?"

Premier Blaine Higgs announced Wednesday that the province will move to Phase 2 of its "path to green" literally overnight. It will take effect at midnight Wednesday, just 24 hours after Phase 1 began.

Phase 2 was triggered because more than 20 percent of people aged 65 or older have now had their second dose of vaccine.

The province says the shift is also based on low hospitalization rates, though there's no quantifiable threshold for that, and on all health zones being in the yellow alert level.

Risk management key, says Russell

Russell acknowledged Wednesday the change is not risk-free.

But she said the COVID-19 case rate in the province has tended to be a consistent fraction of the rate elsewhere in Canada, and with cases dropping elsewhere in the country, post-opening cases should also track at the same lower rate.

That fact, combined with the pace of vaccination, "we anticipate that we will be able to continue with that same level of protection of our health care system as we move forward, but time will tell. … There is nothing with the pandemic that is without risk." 

She also said that she expects cases to rise but thanks to vaccination rates, a lot of people who have COVID-19 will have mild symptoms and won't need hospitalization, making the situation manageable.

Vaccination is good in that it makes the wood less dry if new sparks come, but it won't stop it by itself.​- Malgorzata Gasperowicz, biologist.

Higgs said this week that having set out the Phase 2 target in late May, he was obligated to honour it even if it arrived quickly after Phase 1. 

"It had some very clear guidelines on what to achieve, and I don't think New Brunswickers would have been been very happy if we had delayed when they had worked so diligently to achieve the outcomes," he said. "People need to be rewarded for great behaviour."

He also pointed out that masking and distancing requirements remain in effect. 

But Gasperowicz said New Brunswick should wait for higher second-dose numbers because of the risk from the Delta variant, which spreads more easily. 

"Once it's imported to a place and it starts growing, it's very difficult to stop it," she says.

While overall cases in Alberta are dropping, she adds, the number of Delta cases there has been rising to the point that she believes a fourth wave is possible there during the summer. 

She points out that a single vaccine dose is only 30 per cent effective against that variant--yet someone from Ontario or Quebec with a single shot, and exposed to the Delta variant, could arrive in New Brunswick within days and not have to self-isolate.

And if that person goes to a restaurant operating at full capacity, another change taking effect with Phase 2, they could sit a few feet away from a New Brunswicker with only one shot, or whose second shot was a few days ago and isn't fully effective yet. 

"Vaccination is good in that it makes the wood less dry if new sparks come, but it won't stop it by itself," says Gasperowicz.

Russell said the province will continue to monitor compliance with remaining health measures and conduct testing when it's needed. 

Phase 3 of New Brunswick's plan would see the lifting of all pandemic restrictions when 75 per cent of the eligible population has two doses. The target date is Aug. 2, though Higgs said Tuesday the province may get there sooner.

Deonandan says the threshold, the equivalent of 66.5 percent of the total population, "is not a bad place to get to" even if it falls short of herd immunity.

Deonandan says eliminating COVID-19 altogether via herd immunity is likely impossible in Canada because people are unlikely to get vaccinated at a high enough rate and they don't have the patience for the strict measures required to eliminate the virus.

So the goal is to control the virus through what he called "practical herd immunity."

"Practical herd immunity simply means we can open up society and tolerate outbreaks that will happen almost exclusively among the unvaccinated, with the expectation that Public Health can manage that scenario and it will not challenge our health care capacity."