What are the current COVID-19 risks and what’s next? The head of Ontario’s science table answers

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We’ve heard the names – alpha, beta, delta, gamma – of all sorts of concern when it comes to COVID.

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And just a few days ago, a new variant emerged in South Africa – b.1.1.529, now called Omicron by the WHO – that is even more permeable than Delta, which has already crushed its competitors and has been blown up by Canada and Canada. The rest has become dominant. World.

Cases in one Ontario region doubled in a week due to Delta transmission after provincial restrictions were lifted.

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Now cases are increasing in Toronto as well and there is cause for concern.

“In the presence of the delta, for those who have not yet been fully vaccinated, there is no escape,” said Dr. Peter Juni, an epidemiologist and scientific director of the Ontario COVID-19 Science Advisory Table. If no public health measures are taken, one case of the variant causes an average of seven other infections that are not vaccinated.

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“You get immunity either through vaccination. It’s the easy way,” Juni said. “Or through infection. That’s the risky way.”

Juni says that at least 95 percent of the population would need to be vaccinated to reach herd immunity because of Delta’s “impressive” breeding numbers of 85 percent being pitted against protective vaccines.

There is no evidence yet that the newly discovered Omicron variant is in Canada.

What is known so far, however, is that Omicron outperformed Delta faster than Delta, Juni said.

And the new version probably has an edge on two fronts – it’s more permeable than Delta and makes the immune system evade more easily even in people who have been vaccinated or who have contracted COVID.

On Friday, the federal government said foreigners who had visited seven countries in southern Africa in the past 14 days – South Africa, Mozambique, Botswana, Zimbabwe, Lesotho, Eswatini and Namibia – would be banned from entering Canada.

And Canadian citizens and permanent residents, or others with the right to enter Canada, who have been to those countries will be required to be tested on arrival and quarantined until they receive a negative test result.

We talk to Juni about success cases, weak immunity and how to protect each other during the holidays. Answers have been edited for clarity and length.

Do we know what is the reason for the current increase in COVID cases? Is it the non-vaccinated people, the success cases, the transmittance of the delta variant, or a combination of all three?

It is a combination of all three. More than 85 percent of the eligible population has been fully vaccinated. Even though the vaccine reduces your risk of getting infected by about six times, you will still see significant success cases in vaccination. This should not confuse people, success cases are quite normal. Currently, about half of infections come from 85 percent who have been fully vaccinated and the other half from 15 percent who haven’t been vaccinated. If 100 percent of the entire population were vaccinated, you would only see cases in vaccinations. But that doesn’t mean the vaccine doesn’t work.

At present, uninfected people in the state are almost six times more likely to get infected. And they are about 20 times more likely to end up in the hospital and 25 times more likely to end up in the ICU.

Why do success matters?

Delta is very permeable, and is escaping the immune system partly because our vaccines introduce a spike protein via an mRNA sequence into the body that is still like the wild-type coronavirus. Furthermore, current vaccines are intramuscular, so the types of antibodies we produce – IgG antibodies – act systemically, preventing hospitalization, ICU admission, and death, but sometimes allowing the virus to enter the body. allow to enter and cause mild infection in successful cases. If we had a nasal spray for vaccination, we would generate IgA antibodies, which protect the mucosa in the upper respiratory tract, and we could be better protected from infection. Nasal sprays for vaccination are being discussed right now, so they are still a few years away.

Do we know how much our immunity is decreasing?

In Ontario, the range of protection offered by vaccines has decreased slightly, from about 85 to 87 percent initially, to about 80 to 82 percent now, according to our dashboard, But it’s not just because of decreased (immunity). Thanks to vaccine certificates, it’s also because vaccinated people are now free to expose themselves. They can go to restaurants and eat in crowded dining rooms, while non-vaccinated people cannot. So, we think the success cases that are happening now may be due to a combination of exposure as well as a slight decrease in immunity.

Why do we need a third dose?

Vaccines provide excellent protection against serious disease, but immunity will drop slightly over time. Therefore, the third dose will first start to be important in older age groups and those most vulnerable who are already eligible for the shot. And if we think about continued control of the epidemic, then younger age groups will also need to take a third shot. We don’t yet know where the sweet spot is, what kind of age we want to use. But the shots will not only better protect everyone against hospital and ICU admissions and death, but will also help neutralize immunity against infection. This means you have antibody levels so high that even if the virus does enter the body, it is quickly caught and neutralized by the immune system’s IgG antibodies.

In the presence of this new Omicron variant, anyone who can receive a third dose should receive a dose immediately because every additional improvement of the immune response will be even more important for Omicron than Delta.

Will the third dose stop the success cases?

The third dose will do everything, including the reduction of success cases, as we can see from Israel, when it comes to Delta. (Note: the fourth wave in Israel, which resulted in a rapid increase in infection among vaccinated people, was brought under control by a third dose and public health measures.) But Keep in mind, Israel had an interval of three to four weeks between the first and second doses, whereas we had a much longer interval on average, which is to our advantage. Longer intervals between doses may mean that the immune system is slightly more mature and the immune response is more pronounced after another.

Why should we make Delta or Omicron specific vaccines when we have so many variants? Is it because we can make mRNA vaccines quickly or because we think Delta or Omicron will be here for a long time?

I thought the delta would be around for a long time until it was taken over by another variant that has more mutability and makes it even more easily transmissible, which until two days ago seemed quite difficult to achieve. Basically, if you have a fertility number of seven, like Delta, you’re pretty good as a virus. But now Omicron has really managed to outpace Delta – it’s development in real time.

Now, we will need to see what types of vaccines will be developed over a longer period of time using mRNA technology from Pfizer and Moderna to achieve better protection against Delta, against Omicron and for the future of these two forms of concern. With even more mutation against versions. Right now, we’ll stick to existing mRNA vaccines, which provide excellent protection after two doses, and even more protection after three doses.

We are seeing a rise in cases since the reopening. What do you think about these inconsistent masking policies where we are required to wear masks to shop but not when we are sitting side by side in a packed theater to watch a movie?

I think this is a real problem. People use food and drink in non-dining settings because of not wearing masks. This is fundamentally wrong. So basically what we’ll need to achieve is that employees in playgrounds, theaters, etcetera are doing the same thing as flight attendants. Talking to people, say sorry, take off your mask quickly when you are drinking or eating, and then you need to put it back on. This can make a big difference.

What would you say to people whose holidays are approaching? Should we sing in church, shop in crowded stores, have a holiday party indoors?

Look at Europe and see what kind of mess they are doing. When you look at it, you see that with the temperature dropping, people are moving in, we are all in more trouble than we were before. This is one of the reasons why we start seeing cases rise. This virus is transmitted by air, so it is preferred if people are inside crowded places that are not so well ventilated. Therefore, it is important that everyone should contribute in controlling this pandemic by minimizing their contacts. Ask yourself: Do I really need to go to all five dinner parties I’ve been invited to? And do I really want to go to this crowded restaurant or can I go somewhere that is really well ventilated and not well attended? And do I really need to see all my friends or can I limit my circle of friends with whom I have close contact? But not 50 or 100. And singing in church isn’t really a good idea. Everything helps.

What about traveling outside Canada?

I think the risks associated with travel aren’t that much different nationally and internationally, unless you’re going to places that have significantly higher numbers than ours, which is basically the rest of the northern hemisphere for Ontarians right now. Is. We look a lot better than almost all the people in the world. Fully immunized and having at least one negative PCR or rapid antigen test for people coming to Canada means a powerful reduction in the risk of infection and introducing new forms into the country.

However, the new Omron version means that more requirements will be required for high-risk travelers…

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