Alice Girard-Bossé
Press
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The structure of the virus
At first glance, the variant seems worrying. “The Omicron variant has around fifty mutations, including 32 mutations just on the surface protein”, maintains Alain Lamarre, professor-researcher specializing in immunology and virology at the National Institute for Scientific Research (INRS). By comparison, the Delta variant had only nine mutations on its surface.
“There are certain mutations present in the Omicron variant which, in the past, seemed to be associated with a decline in vaccine immunity,” adds Dr.r Gaston De Serres, epidemiologist at the National Institute of Public Health of Quebec (INSPQ) and member of the Committee on Immunization of Quebec (CIQ).
To infect humans, the surface protein is essential, since it allows the virus to attach to receptors in human cells and inject its genetic material into them.
Current vaccines make it possible to develop antibodies that recognize the surface protein of the virus, which prevents it from attaching to cells. “If the virus changes, one might logically expect the antibodies to be less effective”, summarizes Mr. Lamarre.
In laboratory
Once the virus is observed, the researchers perform a neutralization test in the laboratory. To do this, they will first have to reproduce the Omicron variant in the laboratory, in order to have a good quantity.
“Then we will take serums from vaccinated people, which are stored in banks, and check whether or not they are capable of neutralizing the virus,” says Mr. Lamarre. If the antibodies created by the vaccines have lost their effectiveness, the virus will be able to infect cells.
This is a fairly quick method, since it allows you to get results in about two weeks. However, it is not complete. “The immune system is much more than just antibodies, so the neutralization lab test doesn’t give us all the information we need,” says Lamarre.
We must therefore proceed to another step. “After the laboratory studies, we must confirm with measures of effectiveness in the field”, maintains the Dre Maryse Guay, medical consultant at the Regional Directorate of Public Health of Montérégie and at the INSPQ.
In the field
Epidemiological studies carried out in the field are very reliable, but require much more time and resources. “The ideal technique is to do a study comparing the prevention of infections caused by the Omicron variant in vaccinated and unvaccinated people,” says Dr.re Guay.
To carry out this research, scientists must have access to a large number of people infected with the new Omicron variant. “In Canada, we can’t do these studies because we don’t have enough cases,” says Dr.r From Serres.
However, these studies could be done in South Africa, where the virus is spreading further. The low vaccination coverage in South Africa, which stands at only 24%, may however complicate the studies, specifies Mr. Lamarre.
Although these studies cannot be done immediately in Canada, they could be done in the coming months, if the number of cases of the Omicron variant increases, as was the case with the Delta variant. “With the data from Quebec, we were able to measure that the vaccines we received protect well against the Delta variant”, indicates the Dre Guay.
Create a new vaccine
If, after these steps, the effectiveness of current vaccines with the Omicron variant is not sufficient, pharmaceutical companies will have to develop new vaccines adapted to the genetic code of the Omicron variant.
“We will have to put, in the vaccine, the recipe so that our body produces antibodies against the [protéine de surface] of the new variant ”, explains Dre Guay.
The development of this new vaccine will take about three months with messenger RNA technologies, such as Pfizer and Moderna, argues Lamarre. “It may take a little longer with other vaccines, like AstraZeneca,” he adds.
According to the specialist, a booster dose should be sufficient, since vaccinated people already have a good part of the immune response in memory, which could be stimulated by a booster dose.
Despite the little data currently available on the new variant, the researchers are unanimous: before obtaining results on vaccine efficacy, the population must continue to be vaccinated. “Right now, the Delta variant is still circulating the most in Quebec and the vaccine is very effective against the Delta variant,” recalls Mr. Lamarre.
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Related
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Alice Girard-Bossé
Press
–
The structure of the virus
At first glance, the variant seems worrying. “The Omicron variant has around fifty mutations, including 32 mutations just on the surface protein”, maintains Alain Lamarre, professor-researcher specializing in immunology and virology at the National Institute for Scientific Research (INRS). By comparison, the Delta variant had only nine mutations on its surface.
“There are certain mutations present in the Omicron variant which, in the past, seemed to be associated with a decline in vaccine immunity,” adds Dr.r Gaston De Serres, epidemiologist at the National Institute of Public Health of Quebec (INSPQ) and member of the Committee on Immunization of Quebec (CIQ).
To infect humans, the surface protein is essential, since it allows the virus to attach to receptors in human cells and inject its genetic material into them.
Current vaccines make it possible to develop antibodies that recognize the surface protein of the virus, which prevents it from attaching to cells. “If the virus changes, one might logically expect the antibodies to be less effective”, summarizes Mr. Lamarre.
In laboratory
Once the virus is observed, the researchers perform a neutralization test in the laboratory. To do this, they will first have to reproduce the Omicron variant in the laboratory, in order to have a good quantity.
“Then we will take serums from vaccinated people, which are stored in banks, and check whether or not they are capable of neutralizing the virus,” says Mr. Lamarre. If the antibodies created by the vaccines have lost their effectiveness, the virus will be able to infect cells.
This is a fairly quick method, since it allows you to get results in about two weeks. However, it is not complete. “The immune system is much more than just antibodies, so the neutralization lab test doesn’t give us all the information we need,” says Lamarre.
We must therefore proceed to another step. “After the laboratory studies, we must confirm with measures of effectiveness in the field”, maintains the Dre Maryse Guay, medical consultant at the Regional Directorate of Public Health of Montérégie and at the INSPQ.
In the field
Epidemiological studies carried out in the field are very reliable, but require much more time and resources. “The ideal technique is to do a study comparing the prevention of infections caused by the Omicron variant in vaccinated and unvaccinated people,” says Dr.re Guay.
To carry out this research, scientists must have access to a large number of people infected with the new Omicron variant. “In Canada, we can’t do these studies because we don’t have enough cases,” says Dr.r From Serres.
However, these studies could be done in South Africa, where the virus is spreading further. The low vaccination coverage in South Africa, which stands at only 24%, may however complicate the studies, specifies Mr. Lamarre.
Although these studies cannot be done immediately in Canada, they could be done in the coming months, if the number of cases of the Omicron variant increases, as was the case with the Delta variant. “With the data from Quebec, we were able to measure that the vaccines we received protect well against the Delta variant”, indicates the Dre Guay.
Create a new vaccine
If, after these steps, the effectiveness of current vaccines with the Omicron variant is not sufficient, pharmaceutical companies will have to develop new vaccines adapted to the genetic code of the Omicron variant.
“We will have to put, in the vaccine, the recipe so that our body produces antibodies against the [protéine de surface] of the new variant ”, explains Dre Guay.
The development of this new vaccine will take about three months with messenger RNA technologies, such as Pfizer and Moderna, argues Lamarre. “It may take a little longer with other vaccines, like AstraZeneca,” he adds.
According to the specialist, a booster dose should be sufficient, since vaccinated people already have a good part of the immune response in memory, which could be stimulated by a booster dose.
Despite the little data currently available on the new variant, the researchers are unanimous: before obtaining results on vaccine efficacy, the population must continue to be vaccinated. “Right now, the Delta variant is still circulating the most in Quebec and the vaccine is very effective against the Delta variant,” recalls Mr. Lamarre.
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