Are we ready to face Omicron, this worrying new variant that is starting to spread around the world, including at home? Experts are advancing with caution, given the little data currently available on the strike force of this new player, who has undergone many changes to its surface. Interview by Pauline Gravel.
Are we well equipped to take on the new Omicron variant?
“The preventive measures still in place should help us to face it”, underlines the DD Caroline Quach-Thanh, microbiologist-infectious disease specialist at CHU Sainte-Justine.
The Dr Don Vinh, microbiologist-infectious disease specialist at the MUHC, has some doubts. “Did we really learn from the last year and a half? We understand that the virus is transmitted by air, but have the appropriate measures been put in place to deal with it? Has the ventilation been improved? He wonders, while affirming that we should reconsider the proper wearing of masks among high school students and the return to telework.
UQAM virology specialist Benoit Barbeau points out that the Pfizer and Merck companies have developed new antivirals that appear to be very effective. “We must wait until the scientific data concerning these two antivirals are published and peer-reviewed to know objectively the efficacy and safety, and to know which categories of people could benefit from them before using them”, warns the Dr Vinh, while indicating that monoclonal antibodies are administered successfully.
Will the vaccines we have received protect us against Omicron?
We don’t know yet. The manufacturers are checking it out. We should have the answer in a few weeks.
Virologist Andrès Finzi, from the CHUM Research Center, and Benoît Barbeau point out that Omicron has mutations that other variants also exhibited and which mean that these variants are less well neutralized by the antibodies induced by the vaccines than we have received.
“The new Omicron variant exhibits 32 changes affecting its spicules [ces dards à la surface du virus] and a dozen affecting the site that binds to the receptor of the cells it infects. With all of these changes, chances are that the antibodies we make after receiving the vaccine that was designed against the original virus are not as specific and therefore probably not as effective at neutralizing that variant. However, the immune response generated by vaccination has many facets. Even if we see in the laboratory that the antibodies are less efficient at neutralizing this variant, that does not mean that the vaccine will not work. There may be some protection, but it could be less, ”explains Mr. Barbeau.
“It is likely that the vaccine will confer some protection against this new variant, but it is not known how extensive this protection will be. It will be necessary to carry out tests to clarify it, “advances Mr. Finzi cautiously.
The DD Quach believes that “the vaccination could nevertheless protect against serious infections, not thanks to antibodies, but to the cellular immunity that the vaccinated people will have developed, because this immunity is much less specific, it is able to pick up a wider [éventail de virus] “.
Would a third dose of vaccine help protect us against Omicron?
The Dr Vinh believes that a third dose would be needed to stop the transmission of Omicron in our population. However, this is not the opinion of Professors Finzi and Barbeau, who consider it more relevant to administer the vaccine to populations of the world who are not very vaccinated and among which variants such as Omicron emerge.
Prohibit travelers from the few countries where we find does the Omicron variant appear to youan adequate measure?
“It’s a bit of a sword in the water, in the sense that this variant, which seems highly transmissible, has already circulated quite a bit. A few cases have already been identified in Canada. If we want to intervene at the borders, it would be better to act globally and target all travelers arriving in Canada, and not just those coming from certain countries in particular, ”explains Mr. Barbeau.
“We should reinstate a mandatory quarantine for all travelers from all origins, because the virus has already spread everywhere. This mandatory 14-day quarantine should also be accompanied by a second screening test carried out five to eight days after the return of the traveler, ”advises Dr.r Vinh.