Modelling warns of COVID crunch time
Hospitalization numbers projected to rise above capacity in May unless virus is controlled
Transmission of the coronavirus must be reduced by about 40 per cent from March's rate of spread to bend the pandemic curve and stop hospitalizations from rising above capacity, according to an independent modelling report released Wednesday.
The detailed information is the first to be released by a B.C. COVID-19 modelling group comprised of academics from the University of B.C., Simon Fraser University and the University of Victoria, as well as consultants in data analytics.
The group, which has been together for more than a year, plans to begin releasing regular reports.
The report's modelling found that hospitalization numbers are projected to rise above capacity in May unless virus transmission, driven by a rise in virus variants that spread more easily and cause worse outcomes, is brought under control.
It is possible that measures already taken by the province such as shutting down indoor dining and targeting vaccinations at hot spots such as Whistler and Prince Rupert will bring down the transmission rate, but it's not likely enough to halt the exponential growth, said University of B.C. epidemiologist Sarah Otto, one of the modelling group's members and editor of the report. “The problem is that the vaccines are rolling out a constant number every day. Variants are growing exponentially. And you can't compete with exponential growth,” said Otto, a zoologist who specializes in mathematical modelling.
Otto said the group decided to release the information because it is important to communicate openly with the public. The province has also released modelling results periodically, but has come under some criticism for its transparency around variant data.
The modelling group suggests that B.C.'s vaccination program needs to swiftly target those with the most contacts
so that hospitalization rates can be reduced in the next two to three months.
The group also suggests using rapid testing to detect and isolate people without symptoms, for example where there's been a workplace exposure, and targeting vaccinations
to sites and sectors of the population most at risk.
The report notes that growth of variants of the virus, in particular the U.K. variant (P.1.1.7) and the Brazil variant (P.1) are driving the recent rise in cases.
The modelling in the report
shows that even if transmissions were to be reduced by 30 per cent, the rate of spread would continue to increase, and hospitalizations and critical care units would be at risk of reaching capacity.
According to the latest information from B.C. public health officials, virus variants account for about 50 per cent of new cases.
Caroline Colijn, a Simon Fraser University professor who is also a member of the modelling group, said the province can't rely on vaccinations to prevent the surge in cases and hospitalizations, at least not in the short term.
That is why it is important to reduce transmissions with measures such as targeting hot spots and increasing rapid testing, but also through individual actions, said Colijn.
“We're probably at more risk now than we ever have been in the general community in B.C., even though we're also sick of it, and we don't want to be doing distancing,” observed Colijn.
University of B.C. epidemiologist Daniel Coombs noted the key take-away from the modelling, which put together work from several scientists, is that vaccinations alone are not going to prevent a big wave cresting in May, not just cases but hospitalizations.
Coombs said it was important to provide the public this independent modelling work that shows the complexity of what is happening now. That includes changing behaviours, virus variants that spread quicker and the rate of the vaccine rollout, he said.