We’ve heard the names: Alpha, Beta, Delta, Gamma, all worrying variants when it comes to COVID.
And just 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 transmissible than Delta, which has already crushed its competitors and has become dominant in Canada and the Rest of the countries. world.
Delta’s communicability led to cases doubling in a week in one area of Ontario after provincial restrictions were lifted.
Now cases are also on the rise in Toronto and there are reasons for concern.
“In the presence of Delta, for those who are not fully vaccinated yet, there is no escape,” said Dr. Peter Juni, epidemiologist and scientific director of the Ontario COVID-19 Scientific Advisory Board. One case of the variant leads to another seven infections in the unvaccinated on average, if public health measures are not taken.
“Or you get immunized through vaccination. That’s the easy way, ”Juni said. Or through an infection. That’s the risky way. “
Juni says that at least 95 percent of the population would need to be vaccinated to achieve herd immunity due to Delta’s “impressive” breeding numbers, compared to vaccines that protect 85 percent.
There is no evidence yet to suggest that the newly discovered Omicron variant is found in Canada.
What is known so far, however, is that Omicron outperformed Delta faster than Delta outperformed Alpha, Juni says.
And the new variant probably has an advantage on two fronts: It is more transmissible than Delta and it evades the immune system more easily even in people who are vaccinated or who have contracted COVID.
On Friday, the federal government said foreigners who have been to seven southern African countries – South Africa, Mozambique, Botswana, Zimbabwe, Lesotho, Eswatini and Namibia – in the past 14 days will be barred from entering Canada.
And Canadian citizens and permanent residents, or other persons entitled to enter Canada, who have been to those countries, will need to be tested upon arrival and quarantined until they receive a negative result.
We spoke to Juni about breakthrough cases, lowered immunity, and how to protect each other while on vacation. Responses have been edited for clarity and length.
Do we know what is causing the current increase in COVID cases? Is it unvaccinated, breakthrough cases, Delta variant transmissibility, or a combination of all three?
It is a combination of all three. More than 85 percent of the eligible population is fully vaccinated. Even though the vaccine reduces your risk of getting infected about six times, you will still see many cases of breakthrough in those vaccinated. It shouldn’t confuse people, break-up cases are absolutely 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 were vaccinated, you would only see cases in the vaccinated. But this does not mean that the vaccine does not work.
Unvaccinated people are still about six times more likely to be infected in the province at this time. And they continue to be roughly 20 times more likely to end up in the hospital and 25 times more likely to end up in the ICU.
Why do breakdowns occur?
Delta is highly transmissible and is partially bypassing the immune system because our vaccines introduce a spike protein through the mRNA sequence into the body that is still like that of the wild-type coronavirus. In addition, current vaccines are intramuscular, therefore, the type of antibodies that we generate, IgG antibodies, act systemically, preventing hospitalization, admission to the ICU and death, but sometimes they allow the virus to enter the body and cause milder infections in advance 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 against infections. Nasal sprays for vaccination are being discussed right now, so there are still a couple of years to go.
Do we know how much our immunity is decreasing?
In Ontario, the degree of protection provided by vaccines has decreased somewhat, from initially around 85 to 87 percent to now around 80 to 82 percent. according to our board. But this is not only due to waning (immunity). Thanks to vaccination certificates, it is also because vaccinated people now have more freedom to be exposed. They can go to restaurants and eat in a crowded dining room, while unvaccinated people cannot. Therefore, we believe that the breakthrough cases that are occurring now may be due to a combination of exposure, as well as a small decrease in immunity.
Why do we need a third dose?
Vaccines provide excellent protection against serious diseases, but immunity will decrease somewhat over time. Therefore, a third dose will start to be important first in the oldest age groups and the most vulnerable people who are already eligible for the vaccine. And if we think about the continuous control of the pandemic, also the younger age groups will need to receive a third vaccine. We still don’t know where the sweet spot is, what kind of age cut we want to use. But vaccines will not only better protect everyone against admission and death in the hospital and ICU, they will also provide neutralizing immunity against infections. That means it has such high antibody levels that even if the virus enters the body, it is immediately trapped and neutralized by IgG antibodies from the immune system.
In the presence of this new variant of Omicron, anyone who can receive a third dose should receive one immediately because each further enhancement of the immune response will be even more important to Omicron than to Delta.
Will the third dose stop the ruptures?
The third dose will do everything, including a reduction in breakthrough cases, as we can see in Israel, when it comes to Delta. (Note: a fourth wave in Israel, which resulted in a sharp increase in infections in vaccinates last fall, was controlled by third doses and public health measures.) Note that Israel has had a three to four week interval between the first and second doses, whereas we have had much longer averaging intervals, which is beneficial to us. Longer intervals between doses may mean that the immune system matures a bit more and that the immune response after the second is more pronounced.
Why should we make specific Delta or Omicron vaccines when we’ve had 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 Delta would be around for a long time unless it was replaced by another variant that has more mutations and makes it even more easily transmissible, which seemed quite difficult to achieve until two days ago. Basically, if you have a breeding number of seven, like Delta, you are pretty good as a virus. But now Omicron managed to outperform Delta, that’s real-time evolution.
Now, we will need to see what type of vaccines will be developed in the longer term using mRNA technology from Pfizer and Moderna to achieve better protection against Delta, against Omicron and against future versions of these two worrying variants with even more mutations. Right now, we’ll stick with existing mRNA vaccines, which provide excellent protection after two doses, and even more protection after three doses.
We are seeing an increase in cases since the reopening. What do you think of these inconsistent masking policies, where we are required to wear masks to shop but not when sitting next to each other in a crowded theater watching a movie?
I think it is a real problem. People use eating and drinking in non-eating settings as a reason not to wear their masks. That is fundamentally wrong. So, what we would have to achieve as basic is that the personnel of the sports stadiums, cinemas, etc., are doing the same as the flight attendants. Talking to people, beg your pardon, you only quickly remove the mask when you are drinking or eating and then you have to put it back on. It could make a big difference.
What would you say to people with the arrival of the holidays? Should we be singing in church, shopping in crowded stores, having parties indoors?
Look at Europe and look at the mess they are having. When you see that, you realize that with the temperature dropping, people moving in, we all tend to have more problems than before. That is one of the reasons we started to see an increase in cases. The transmission of this virus is transmitted through the air, which is why he loves that people are inside crowded spaces that are not as well ventilated. So the important thing is that everyone should contribute to controlling this pandemic simply by reducing their contacts a little. Ask yourself: Do I really need to go to the five dinners I’ve been invited to? And do I really want to go to this crowded restaurant or could I go somewhere else that’s really airy and not that crowded? And do I really need to see all my friends or can I restrict my circle of friends that I have close contact with to maybe 10? But not 50 or 100. And singing in church is not really a good idea. Everything helps.
What about travel outside of Canada?
I think the risks associated with travel are not that different nationally and internationally, unless you’re going to places that have considerably higher numbers than we do, which for Ontarians right now is basically the rest of the Northern Hemisphere. We look great compared to almost everyone else in the world. Being fully vaccinated and having at least a negative PCR or rapid antigen test for people coming to Canada means a powerful reduction in the risk of introducing infections and new variants into the country.
However, the new variant of Omicron means that more requirements will be needed for travelers from high-risk countries, which at the moment is 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.
Reference-www.thestar.com