Gagandeep Grewal, front right, and his wife Harpreet Grewal, left, each receive their first dose of the Pfizer COVID-19 vaccine during an immunization clinic at the Gurdwara Dukh Nivaran Sahib, in Surrey, B.C., on Friday, May 14, 2021. Gurdwara leadership reached out to the Sikh community and registered and booked a total of 800 people for vaccinations during two clinics held in the dining hall of their temple last week and Friday. The East Newton neighbourhood is an area that Fraser Health has identified as one where a high rate of COVID-19 transmission is still occurring. THE CANADIAN PRESS/Darryl Dyck

Gagandeep Grewal, front right, and his wife Harpreet Grewal, left, each receive their first dose of the Pfizer COVID-19 vaccine during an immunization clinic at the Gurdwara Dukh Nivaran Sahib, in Surrey, B.C., on Friday, May 14, 2021. Gurdwara leadership reached out to the Sikh community and registered and booked a total of 800 people for vaccinations during two clinics held in the dining hall of their temple last week and Friday. The East Newton neighbourhood is an area that Fraser Health has identified as one where a high rate of COVID-19 transmission is still occurring. THE CANADIAN PRESS/Darryl Dyck

Will B.C. see a 4th wave? Researcher says it’s a battle of vaccines versus the variants

Sarah Otto recommends that even fully vaccinated individuals wear masks in crowded indoor areas

It’s not yet clear what the next wave of COVID-19 will look like for B.C., but a University of B.C. researcher said British Columbians should keep their masks on for now, and get fully vaccinated if they have not already.

Sarah Otto, a professor at UBC and part of an independent COVID-19 modelling group, said it’s not clear yet if B.C.’s July 1 move in Step 3 of its reopening plan would lead to a serious jump in case counts.

“There’s a slight uptick but it’s too early to tell if that uptick is going to be the start of more to come or just fluctuations that can happen due to single events,” Otto said. “So that’s the problem when the numbers get this low; single events can dominate.”

However, clues can be seen by analyzing other countries. The United Kingdom is reporting a 32.6 per cent, or 64,368 case increase in the past seven days. In the same time period, hospitalizations have gone up by 46.8 per cent, or 1,254 patients, and deaths by 47.7 per cent, or 83 people.

Otto said that although the U.K. has a higher proportion of people with second doses – more than 70 per cent of adults, compared to under 60 per cent in B.C. – they have fewer young people vaccinated due to their rollout plans.

“It’s really hard to compare, but I would say that we shouldn’t rest on our laurels and say that we’ll be okay,” she said, adding that if the U.K. continues to see hospitalizations growing at the current rate it would only take two to four weeks for hospitals to be overwhelmed.

A recent analysis of the more infectious Delta variant in the United States showed positive growth rates in 48 out of 50 states.

“We very much expect the same thing to happen here. Delta was just slightly declining before we opened up,” she said. “We expect it to rise.”

How much it will rise however, depends on how people act. Otto said that if the majority of people take full advantage of restrictions lifting – in other words, attending large gatherings, not wearing masks indoors – then it will rise faster.

Otto said that the battle now was between the vaccines and the variants.

“Delta appears to have a transmission advantage twice that of what we were dealing with before without the B.1.1.7 (Alpha) variant,” she said, referring to original “wild type” COVID that caused the first waves just over 16 months ago.

READ MORE: COVID-19 deaths and cases rising again globally

Otto said that if British Columbians double their current activity, or contact levels, cases of the Delta variant could double every 10 days. In the Netherlands, she said, where Delta is surging, they’re seeing those variant cases double every week.

That rapid rate of transmission, Otto said, has consequences for the level of vaccination B.C. will need to reach herd immunity.

“It’s absolutely the case that the vaccine levels that we have probably were enough for original variants,” she said.

“With millions of cases worldwide, we’re seeing the evolution of a lot of genetic diversity within the virus and more and more adaptive mutation of variants to humans and spread among human.”

However, Otto said that “vaccinations are an incredible win,” regardless of the new variants.

“We would be in a terrible state right now if we didn’t have vaccines at the level that we do and the efficacy against hospitalization and death is humongous – over 90 per cent even Delta.”

The question of how well Delta transmits from vaccinated individuals – even if they don’t feel sick, or have a mild case – is yet to be answered, she noted, but said that if even 10 per cent of immunized people can spread the virus that becomes an enormous risk for unvaccinated people.

Those include children, although Otto said that even with Delta they are showing a “very low risk of severe cases.” However, even with a lower risk, if Pfizer and Moderna vaccines are approved for children under the age of 12, Otto said that vaccinations in younger kids this fall could do a lot to slow overall transmission.

For now, Otto said, she recommends that people take advantage of warm weather and socialize outdoors, where the risk is lower.

“I would highly recommend that we still wear masks in indoors in crowded areas, even if we’re fully vaccinated,” she said. “I know that that’s not the recommendation of the province but I would say there’s still too much uncertainty about how much transmission occurs from vaccinated individuals and we still have many people unvaccinated and at risk in this province.”


@katslepian

katya.slepian@bpdigital.ca

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