The Chronicle Herald (Metro)

Immunizati­on expert says pandemic is not over

Ottawa doctor urges caution


OTTAWA — If vaccinatio­n rates continue to climb steadily and COVID-19 cases remain low, Ontario could be on track to move out of Step 3 early in August — meaning most pandemic restrictio­ns could be lifted.

But should they be? Ottawa's Dr. Kumanan Wilson, a senior researcher at the Ottawa Hospital Research Institute with a specialty in immunizati­on, says no.

Despite the positive trends in Ottawa and across Ontario, the pandemic is not over yet, he said. There are many factors still in play, some of which are not well understood. Those include whether the protection offered by COVID-19 vaccines will wane over time and what level of community vaccinatio­n is required to achieve herd immunity against the highly transmissi­ble Delta variant.

“We are in a much better place than we were,” Wilson said. “Vaccinatio­ns worked. We have reduced the circulatin­g virus, but there is always the risk of reintroduc­tion.”

And vaccinatio­n rates are not yet high enough to provide protection against that.

As other jurisdicti­ons drop pandemic restrictio­ns and watch cases begin to rise, Wilson says Ontario has been cautious, which has been paying dividends as cases drop while vaccinatio­n rates rise.

He would like to see Ontario stay the course — meaning masks should still be required in many circumstan­ces, outdoor activities should continue to be encouraged and improved indoor ventilatio­n must be made a priority.

This week, the United Kingdom lifted all pandemic restrictio­ns on what was being called “Freedom Day” even as cases driven by the Delta variant are rising. The U.K. seems to be resigned to living with COVIID-19 rather than trying to eliminate it, he said.

Wilson said the U.K. and elsewhere offered lessons for how Ontario and Canada should move forward in coming months. The real test, he said, will be when people begin moving back indoors after the summer.

In 2020, cases counts also plummeted during the summer, but spiked again in the fall.

The difference this year is vaccine.

After a slow start, Canada is now regarded as a global success story when it comes to vaccinatio­n.

In Ottawa, 82 per cent of people over 12 have at least one shot and 64 per cent are fully vaccinated with two. Ottawa is slightly above the provincial average. Just over 80 per cent of Ontario residents over 18 have had at least one dose and about 64 per cent have had two.

But that is still far from enough to achieve herd immunity, Wilson said, especially with the emergence of the Delta variant.

Based on the dominant variant's reproducti­on number — how many secondary infections a single infection causes — and vaccine effectiven­ess, Wilson said herd immunity can be estimated, meaning how many people have to be fully vaccinated to achieve it.

With the original variant, vaccinatio­n rates of around 63 per cent would have achieved her immunity, he said, but with Delta that number is likely somewhere between 83 per cent and as high as 99 per cent.

Ontario has done well to ramp up vaccinatio­n rates in recent months, but it still has a long way to go to achieve a level that would largely prevent transmissi­on of COVID-19 in the community, especially with children under 12 still ineligible for vaccines, Wilson said.

In the weeks before the weather turns colder and people begin spending more time indoors, it is crucial to do a major push to vaccinate as many people as possible, he said.

Ontario's Chief Medical Officer, Dr. Kieran Moore, said Thursday that the province was closely monitoring vaccinatio­n rates. He said incentives to get the vaccine were reasonable and the province would look at all possibilit­ies to achieve a high immunizati­on rate.

Wilson noted that the last 10 per cent is often the most difficult to get to for a variety of reasons.

Among other things, Wilson would like to see COVID-19 vaccines treated the way other vaccines are for school children and made mandatory. As with other vaccines, parents could seek exemptions, but their children would have to be excluded from school if there was an outbreak.

But vaccines alone do not get rid of diseases, Wilson said. “It is always vaccines in combinatio­n with public health measures.

“It is premature to say we are done, but I think, if we can control (the pandemic) with smart policies, we can avoid lockdowns. If don't have the right policies, (lockdowns) could be back.”

 ?? ERROL MCGIHON • POSTMEDIA NEWS ?? Vaccines alone do not get rid of diseases, Dr. Kumanan Wilson says. “It is always vaccines in combinatio­n with public health measures."
ERROL MCGIHON • POSTMEDIA NEWS Vaccines alone do not get rid of diseases, Dr. Kumanan Wilson says. “It is always vaccines in combinatio­n with public health measures."

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