What are the current COVID-19 risks and what’s next? The head of Ontario’s science table answers
We’ve heard the names – Alpha, Beta, Delta, Gamma – all variants of concern when it comes to COVID.
And a few days ago, a new variant appeared in South Africa – B.1.1.529, now called Omicron by the WHO – which is even more transferable than Delta, which has already crushed its competitors and has become dominant in Canada and the rest of the world.
Delta’s portability led to cases doubling in one week in an area of Ontario after provincial restrictions were lifted.
Now cases are also rising in Toronto and there is reason to be concerned.
“In the presence of Delta, for those who are not yet fully vaccinated, there is no escape,” said Dr. Peter Juni, an epidemiologist and scientific director of the Ontario COVID-19 Science Advisory Table. One case of the variant leads to an average of seven other infections in the unvaccinated if no public health measures are taken.
“Either you become immune through vaccination. That’s the easy way out, ”said Juni. “Or through infection. That’s the risky way.”
June says at least 95 percent of the population must be vaccinated to achieve herd immunity because of Delta’s “impressive” reproduction rates, which are set against vaccines that are 85 percent protective.
There is as yet no evidence to suggest that the newly discovered Omicron variant is in Canada.
What is known so far, however, is that Omicron outperformed Delta faster than Delta outperformed Alpha, says June.
And the new variant probably has an advantage on two fronts – it is more transferable than Delta and more easily evades the immune system even in people who have been vaccinated or have received COVID.
On Friday, the federal government said that foreigners who have been to seven countries in southern Africa – South Africa, Mozambique, Botswana, Zimbabwe, Lesotho, Eswatini and Namibia – would be banned from entering Canada for the past 14 days. .
And Canadian citizens and residents or others with the right to enter Canada who have been to these countries must be tested on arrival and quarantined until they receive a negative test result.
We talk to June about breakthrough cases, declining immunity and how to protect each other during the holidays. The answers are edited for clarity and length.
Do we know what is causing the current increase in COVID cases? Is it unvaccinated people, breakthrough cases, the transferability of the Delta variant or a combination of all three?
It’s a combination of all three. More than 85 percent of the eligible population is fully vaccinated. Although the vaccine reduces your risk of becoming infected about six times, you will still see a number of breakthrough cases in the vaccinated. It should not confuse people, breakthrough cases are completely normal. Currently, about half of the infections come from the 85 percent who are fully vaccinated and the other half come from the 15 percent who are not vaccinated. If 100 percent of the entire population had been vaccinated, one would only see cases in the vaccinated. But that does not mean that the vaccine does not work.
Unvaccinated people are still about six times more likely right now in the province to become infected. And they are still about 20 times more likely to end up in the hospital and 25 times more likely to end up in the intensive care unit.
Why do breakthrough cases arise?
Delta is highly transmissible and partially eludes the immune system because our vaccines introduce a peak protein through the mRNA sequence into the body, which is still similar to that of wild-type coronavirus. In addition, current vaccines are intramuscular, therefore the type of antibodies we generate – IgG antibodies – act systemically and prevent hospitalization, intensive care unit and death, but sometimes allow the virus to enter the body and cause milder infections in breakthrough cases. If we had a nasal spray for vaccination, we would generate IgA antibodies, which protect the lining of the upper respiratory tract, and we might be better protected against 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 declining?
In Ontario, the amount of protection that vaccines provide has dropped slightly, from originally around 85 to 87 percent to now around 80 to 82 percent, according to our dashboard. But it is not only because of (immunity) declining. Thanks to vaccine certificates, it is also because vaccinated people are now freer to expose themselves. They can go to restaurants and eat in a crowded dining room, whereas non-vaccinated people can not. So we think the breakthrough cases that are happening now may be due to a combination of exposure as well as a small drop in immunity.
Why do we need a third dose?
The vaccines provide excellent protection against serious illness, but immunity will drop slightly over time. Therefore, a third dose will begin to be important only in older age groups and the most vulnerable people who are already eligible for the shot. And if we think about continuing to control the pandemic, then younger age groups should also get a third shot. We do not yet know where the sweet spot is, what age limit we will use. But the shots will not only protect everyone better from hospitalization and intensive care unit and death, but also provide neutralizing immunity to infection. This means that you have antibody levels that are so high that even though the virus enters the body, it is immediately captured and neutralized by the immune system’s IgG antibodies.
In the presence of this new Omicron variant, anyone who can get a third dose should get one right away, because any further improvement in the immune response will be even more important for Omicron than for Delta.
Will the third dose stop breakthrough cases?
The third dose will do everything, including a reduction in breakthrough cases that we can see from Israel when it comes to Delta. (Note: A fourth wave in Israel, which ultimately resulted in a sharp increase in infections in the vaccinated, was brought under control by third doses and public health measures.) But keep in mind that Israel has had an interval of three to four weeks between the first and second dose, while on average we have had much longer intervals, which is to our advantage. Longer dose intervals may mean that the immune system matures a little more and that the immune response after the second dose is more pronounced.
Why should we make Delta- or Omicron-specific vaccines when we have had so many variants? Is it because we can make mRNA vaccines fast, or because we think Delta or Omicron will be here for a long time?
I thought Delta would exist for a long time unless it will be taken over by another variant that has more mutations and makes it even easier to transfer, which seemed pretty hard to achieve until two days ago. Basically, if you have a reproduction rate of seven, like Delta, you’re pretty good as a virus. But now Omicron actually managed to outperform Delta – it’s real-time development.
Now we need to see what kind of vaccines will be developed in the long term using the mRNA technology from Pfizer and Moderna to achieve better protection against Delta, against Omicron and against future versions of these two variants of concern with even more mutations . Right now, we will stick to the existing mRNA vaccines, which provide excellent protection after two doses, and even more protection after three doses.
We are seeing the number of cases increase since the reopening. What do you think of these inconsistent masking policies where we are required to wear masks on purchases but not when we sit side by side in a crowded cinema and watch a movie?
I think that’s a real problem. People use to eat and drink in surroundings outside eateries as a reason not to wear their masks. That’s fundamentally wrong. So what we basically have to achieve is that the staff at the sports arenas, the cinemas, etc. do the same as the stewardesses. Talk to people, sorry, you only take your mask down quickly when you drink or eat, and then you have to put it on again. It can make a big difference.
What do you want to say to people when the holidays come? Should we sing in church, shop in crowded shops, hold holiday parties indoors?
Look at Europe and look at the mess they have. When you see it, you notice that with falling temperatures, people are moving inside, we all tend to be in more trouble than before. That’s one of the reasons we’re starting to see things rise. Transmission of this virus is airborne, therefore love it if people are inside crowded rooms that are not so well ventilated. So what’s important is that everyone should help control this pandemic by simply reducing their contacts a bit. Ask yourself: Do I really need to go to all five dinner parties that I have been invited to? And do I really want to go into this crowded restaurant, or could I just go somewhere that is really well ventilated and not so 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 to maybe 10? But not 50 or 100. And singing in church is not really a good idea. Everything helps.
How about traveling outside of Canada?
I think the risks associated with travel are not that different nationally and internationally unless you are going to places that have a significantly higher number than we do, which for ontarians right now is basically the rest of the northern hemisphere. We look extremely good compared to almost everyone else in the world. Being fully vaccinated and having at least one negative PCR or rapid antigen test for people coming to Canada means a sharp reduction in the risk of introducing infections and new variants into the country.
However, the new Omicron variant means that there will be a need for additional requirements for travelers from high-risk countries, which right now are South Africa and neighboring countries and perhaps soon the entire continent. We may need to add additional tests, five or seven days after arrival, as well as quarantine requirements.
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