What preliminary data can tell us about the future of Omicron mutants in Canada?

Infectious disease experts are focusing on a pair of numbers that are likely to orbit the Canadian Omicron variant and shape the country’s public health response.

On the one hand, the infection rate of vaccinated individuals. The other is hospitalization.

Peter Juni, an epidemiologist at St. Michael’s Hospital in Toronto and head of science for the COVID-19 Scientific Advisory Board in Ontario, said the combination of the two results in a high vaccination rate for Canada. It says it looks a little better.

Omicrons are certainly widespread, but serious cases in South Africa appear to be predominantly among unvaccinated individuals. Based on Friday’s latest information from a South African colleague, Dr. Juni said unvaccinated individuals could account for more than 85 percent of hospitalizations there.

“It’s really important,” he said. “These are preliminary data, but we can see that there is still a high degree of protection against hospitalization for fully vaccinated people.”

As a corollary to this observation, vaccination against COVID-19 will continue to be the best defense against death and illness, as long as recommended and soon. This means that qualified people need a third dose, those who need it need a second dose, and children aged 5 to 11 years and those who have previously refrained from it have a first dose. Is required. Johnson & Johnson products are an option for people who are reluctant to get the mRNA vaccine.

“We need to optimize our immunity,” he said.

But that would be very good news Vaccines continue to prevent serious illnesses from new variants, It doesn’t translate into a normal business scenario, some experts told The Globe and Mail. This is because there is increasing evidence that Omicron is currently predominant and is more contagious than the delta mutant, which may spread better among vaccinated populations.

If Omicron again demands our self-sacrifice, we are in trouble

If Omicron is reasonably more contagious than Delta, it can be expected to eventually take over, as other variants had before. Due to its timing, it may be further aided by the weakened immunity of the population and the seasonal effects caused by people spending more time indoors together.

As a result, the current infection rate may increase and hospitalization may increase without increasing the severity of the disease. What is relevant to health professionals is how fast this happens and how much burden it puts on Canadian hospitals.

By comparison, both Alpha and Delta variants expelled their predecessors in about 4-5 months when they arrived in Canada. Each was estimated to be about 50 percent more contagious than its predecessor variants.

However, early estimates of Omicron suggest that transmission is 66% to over 500% higher than Delta, a surprising increase.

Troy Day, a computational biologist at Queen’s University in Kingston and also sitting at a science table in Ontario, said:

Dr. Day said that for now, estimates need to be made with large amounts of salt. This is because, like all SARS-CoV-2 variants, omicrons are identified by genomic sequencing. In addition, the data may be exaggerating the penetration of variants because the sequence effort prioritizes where the variants are likely to exist.

Nonetheless, the transmission rate of Omicron has not yet been accurately quantified, but the accumulated evidence explains how Omicron grew rapidly, at least unless some degree of diffusion capacity was improved. Is difficult.

Therefore, Canadians need to be prepared for variants that take off much faster than previously seen, after being established by community dissemination.

“What we’re talking about is a matter of weeks,” said Dr. Juni.

Caroline Colijn, an applied mathematician and disease modeler at Simon Fraser University in Burnaby, British Columbia, said that one of the challenges in accurately predicting what to expect from Omicron is among vaccinated people. He said it was to separate its infectivity from its widespread apparent ability.

Antibody research could shed light on this next week or two weeks, Dr. Colijn added. Vaccine efficacy and Omicron It is more likely to be one to three months away.

On the other hand, individual outbreaks of the subspecies have already shown the potential for antigenic escape. This was reinforced on Friday by reports that at least 50 people were infected with this variant in Oslo, Norway, due to a superspreading event at the company’s Christmas party, where only vaccinated employees were allowed to attend. it was done.

An analysis posted online at the beginning of the week by researchers at the University of South Africa and McMaster University in Hamilton, Ontario, High risk of reinfection associated with Omicron.. This is not a direct measure of vaccine efficacy, but the results are consistent with the idea that the body’s immune response may be better avoided based on the number of genetic changes that Omicron presents. ..

Another confounding factor is that many vaccinated individuals may not know when they will have COVID-19. This makes it difficult to track and evaluate Omicron in Canada.

Catherine Hankins, a professor of public health and artificial health at Magill University, co-chair of the Canadian Immune Task Force, said she and other task force members shed light on the effectiveness of vaccines for people who do not report symptoms. He said he was investigating the feasibility of monitoring tests to guess.

“We’re looking at ways to put together photos to better understand what’s happening across the country,” she said.

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