The third Omicron wave is here and quickly gaining traction—that's the key message of a new report released on Wednesday by the BC COVID-19 Modelling Group, an independent group of researchers and data scientists who have been compiling data-driven reports about the pandemic since April 2021. 

The report highlights the various factors that determine how this wave, driven by the BA.4 and BA.5 Omicron subvariants, will impact BC.

It predicts a rise in hospitalizations in the coming weeks.

PCR testing is almost nonexistent for most people, making tracking the spread extremely challenging. So the modelling group extrapolates the number of cases among the most reliably tested population—people aged 70+. They use the growth rate among that population to estimate how the virus is spreading.

Their models show that cases driven by BA.4 and BA.5, are currently doubling every 11 days among people older than 70, with a growth rate of 6.1% per day. Across Canada, federal data shows the two new variants are spreading at a rate of 8.4% to 12% faster than the BA.2 variant per day. 

The good news in the fight against these new variants, according to the modelling group, is blood sample data showing that, as of May, a lot of people already have antibodies from previous infections or from being vaccinated. The bad news, as we reported on June 30, is BA.4 and BA.5 are able to evade much of these antibodies, and immunity from BA.2 infection could be cut in half 80 to 160 days after infection. 

With this wave of the pandemic, it’s also particularly difficult to predict how far hospitalizations will rise, according to modelling group member Dr. Dean Karlen, because we don’t yet know how fast immunity is waning from the most recent wave of infections.

Karlen’s models can’t accurately tell us whether an infection leads to hospitalization, ever since BC stopped tracking cases through PCR testing last year. It uses the assumption that a BA.4 or BA.5 infection will act like the original Omicron strain—about 35% less likely to lead to hospitalization than the Delta variant. 

Hospitalization data in BC is also not released in a way that allows researchers to understand the current situation. Modelling group member Dr. Sarah Otto told Capital Daily in an interview last month that she has repeatedly asked the province for, but was never given access to, new hospital admission data by day.

“They don't necessarily want external validation or examination of the numbers,” Otto said. “I think if they valued independent external checks, then the data would be more available.”

With all the unknowns and data discrepancies, Karlen says the pandemic is more difficult to analyze and forecast these days. “Modelling of immunity has such a great degree of uncertainty,” he said. “I’m thinking that our projections are quite unreliable beyond three weeks.”

Karlen’s models still show what could happen by the end of July, if these new variants have a growth advantage of 10-12% per day: between 40 to 60 new hospital admissions per day and COVID-related hospital occupancies of up to 600, and 60 in ICU. 

“It will be an incredibly challenging summer and fall,” Saanich Peninsula Hospital ER physician Dr. Jeff Unger told Capital Daily last month, predicting that another wave of COVID-19 patients would exacerbate the already precarious staffing situation at hospitals across the province. At that point, he expects contingency plans, like cancelling elective surgeries and redeploying staff, will have to be brought back. 

The report encourages people to take individual steps—like wearing a mask, choosing to gather in well ventilated spaces, and getting a booster dose of vaccine—to lower their risk of contracting the virus in the absence of broader public health measures. 

Last week, the BC health ministry announced that they will offer fourth doses of vaccines to adults who call and request one. But first, people will be asked to wait for the fall, when the province expects to roll out a bivalent vaccine—one that can combat both Omicron and original strains of the virus—for everyone 12 and older. 

A spokesperson from the health ministry told Capital Daily that those who choose to get a fourth dose now will have to wait at least six months before they can access the expected bivalent shot, under BC’s current immunization strategy. 

Protect Our Province BC, another independent group comprised of healthcare workers and researchers, issued an open letter to the Premier and public health leaders, asking them to allow anyone over age 12 to get a second booster dose, and to let people get a booster three months after their last shot—which NACI guidance allows. 

“Following a vaccine-only strategy for COVID mitigation while at the same time limiting access to vaccines leaves many British Columbians exposed and vulnerable just as the seventh wave is upon us,” reads the letter.

“Our healthcare workers cannot cope with yet another potential onslaught of Covid cases and more Long Covid patients. All efforts should be directed towards limiting this wave’s growing size and impact, while protecting our burnt out healthcare workers and our fragile and failing healthcare system from collapse.”

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Correction on July 15, 2022 at 9:50am: The story has been edited to clarify that BA.4 and BA.5 subvariants are growing 10-12% faster than BA.2 and to correct the number of patients in ICU from up to 300 to 60.