An Ottawa epidemiologist says expanding eligibility of COVID-19 boosters to allow adults to get a fourth dose if they wish could help stem a possible fall wave.

Dr. Raywat Deonandan, epidemiologist and science communicator at the University of Ottawa, says he expects there will be a spike in COVID-19 this fall, as the BA.5 Omicron subvariant becomes the new dominant strain of the virus.

“I fully expect a more dire wave to be upon us by theend of the summer, early fall. It makes sense to be investing now in the tools that will prevent that,” Deonandan told Newstalk 580 CFRA’s CFRA Live with Andrew Pinsent Sunday morning.

Presently, fourth doses are only available to Ontarians who are 60 or older. The latest publicly available Ontario government data show that the death rate for people 60 and older is six times higher for those who are not vaccinated compared to those with a booster, but for residents younger than 60, the death rate is much lower overall and varies much less because of vaccination status.

There is a push to lower the eligibility for fourth doses to 18 in Ontario, with one Ottawa doctor threatening legal action against the provincial government if eligibility is not lowered.

Canada’s Chief Medical Officer and the National Advisory Council on Immunization (NACI) are telling provinces to launch booster dose campaigns in the fall, but Deonandan suggests that is too late.

“By the time you’re getting boosters in the fall, you’re getting protection in early winter, late fall, and it’s probably too late then. It makes sense to get additional protection now,” he said.

Deonandan said he is not in favour of any new lockdowns or business closures.

“Never again,” he said, adding that vaccination is one of the methods that can help prevent the worst outcomes from overwhelming the health-care system and the economy.

“If we really want to curtail transmission in the community, keeping the immunocompromised and people who cannot be vaccinated, that being kids under five, as safe as possible, that means we want to maximize the kind of immunity that prevents actual transmission,” he said. “Right now, a fourth dose does restore much of that ability—not perfectly, but to a large extent—and for months, not permanently, and I think that’s worthwhile achieving.”

Vaccination is not the only tool that can be used to help keep the pandemic under control.

“Vaccination works to a large extent, not perfectly; ventilation absolutely works and we don’t talk enough about that; and strategic mask-wearing works. If we do those things we don’t need to compromise our economy anymore.”

While most government-mandated public health protections have been removed, Deonandan says the pandemic is still not over and the risk of reinfection lingers.

“(BA.5) is definitely achieving greater immune escape, which means that if you had Omicron in the past, you’re going to be re-infected with this variant. Is it more severe? I don’t think so. There’s no obvious data for that. It does underline the fact that natural infection does not promote any kind of lasting immunity, despite what some people online might be saying,” he says.

Deonandan added that the risk of dying or becoming seriously ill from COVID-19 has diminished substantially for most people because they are immunized, and that a fourth dose carries the same safety profile as other doses.

He suggested boosters might continue to be offered “once or twice a year” until a more comprehensive pan-coronavirus vaccine that covers a variety of similar viruses is produced or until the pandemic is under control.

“To me, that’s not an untoward thing to ask of people, if that’s the price of having an open economy, one or two boosters a year.” 

OTTAWA ENTERING NEW WAVE: OPH

Ottawa Public Health says Ottawa is entering a new wave of COVID-19. 

In a statement to CTV News on Monday, deputy medical officer of health Dr. Brent Moloughney said OPH is monitoring rising levels of the virus in the community.

"As we enter a new wave, it’s important to consider your risk, and the risk of those around you when gathering. Ottawa Public Health continues to highly recommend people keep practicing the measures that we know work – being up-to-date with COVID-19 vaccinations, limiting close contacts, staying home if you’re not feeling well, avoiding crowded areas, and wearing a mask," he said.

Moloughney said the decision to expand booster eligibility is in the hands of the provincial health ministry.

In a statement, the Ministry of Health said fourth doses are available for populations at greater risk, but a review of the guidelines is underway.

"We are reviewing NACI’s most recent guidance and will be providing details for fall booster shots over the coming weeks," the statement said.

To date, 64 per cent of residents of Ottawa 12 and older have had a booster shot of the COVID-19 vaccine.

--With files from CTV News Ottawa's Peter Szperling.