B.C. COVID-19 modelling shows what the province's caseload would look like without vaccines

Vancouver -

B.C.'s latest modelling of the COVID-19 pandemic shows transmission of the coronavirus flat or declining across the province, with a previous spike in cases among children seemingly over.

COVID-19's reproductive number is at or below one in all regions of the province, meaning each new confirmed infection is spreading, on average, to just one other person, or fewer.

That's a recipe for continued declining cases, something health officials attribute to widespread vaccination.

B.C.'s medium-range projection, however, assumes a reproductive number of 1.07, with cases remaining relatively flat at their current levels, according to the slides presented by provincial health officer Dr. Bonnie Henry in a news conference Thursday afternoon.

Currently, B.C. is seeing just over 500 new cases of COVID-19 per day, down from a high in the mid-700s earlier in the fourth wave.

Without vaccination, the modelling presentation suggests, the virus' reproductive number would be 3.43, and cases would be growing exponentially, surpassing 8,000 per day in a matter of just a few weeks.

Both projections are based on the existing rules put in place to stop the spread of the coronavirus. If there were no vaccines, B.C. would almost certainly need stricter regulations to keep the virus in check and prevent hospitals from being overwhelmed.

With B.C. headed into what she calls "respiratory season," Henry said the existing rules that have helped the province get its reproductive number down to its current level need to stay in place.

"We have, right now, a fragile balance," the provincial health officer said. "We're going down slowly … This is not the time to let off, in any way, on the things we are doing to protect ourselves, our families and our communities."

Henry listed five things she says B.C. residents should do for their health and that of their community. Four of them relate to vaccination. They are: getting a booster dose when it's your turn; getting your first and second doses right away if you haven't; getting an influenza vaccine to protect against the flu; and registering younger children to get a COVID-19 vaccine as soon as they're eligible.

The fifth thing British Columbians should do, according to Henry, is stay home if they are sick and continue to take actions to limit the spread of COVID-19, such as keeping distance, wearing masks and getting tested as soon as possible when symptoms develop.

Henry described "stubbornly high rates of hospitalization" as B.C.'s "biggest challenge" over the last couple of months.

Health Minister Adrian Dix said more than 100 patients have now been relocated from hospitals in B.C.'s north to other areas of the province.

The province hit a 25-week high for COVID-19-related hospitalizations earlier this week. 

Henry attributed B.C.'s high number of hospitalizations to a combination of factors, including the highly transmissible Delta variant leading to more serious illness among younger people - particularly those who are unvaccinated - as well as breakthrough cases among older people who are fully vaccinated, but whose immune systems mount a less robust response to immunization than younger people's do.

For this reason, older people have been prioritized for booster shots, Henry said. 

Age has always been, and continues to be, the biggest risk factor for COVID-19, the provincial health officer added.

Many of those who died from COVID-19 in B.C. in the month of October were older people who were fully vaccinated, Henry said. The modelling presentation indicated that 46 per cent of the 179 deaths during the month were among those who had received two doses of a vaccine.

Forty-nine per cent of the deaths were among unvaccinated people, and those deaths tended to be among people who were younger, on average, than those who were fully vaccinated and died, according to Henry.

An unvaccinated person is 46 times more likely to die from COVID-19 than a fully vaccinated person of the same age, and 50 times more likely to be hospitalized, Henry said. 

Read through the documents provided by the Ministry of Health: