Tomorrow, all immune to Covid-19? While in just a few weeks, the Omicron variant has established itself in France, its very high contagiousness associated with a lower dangerousness revives the hypothesis, even the hope, of achieving collective immunity against the coronavirus. . “Maybe this is the last variant, maybe this is the last wave, maybe this wave will give us some form of immunity?” “, Asked Monday the Minister of Health, Olivier Véran, on France Inter.
What if the Omicron cocktail and anti-Covid vaccination made it possible to relegate the coronavirus to the rank of a small seasonal virus similar to the common cold? Crazy hope or tangible hypothesis?
Viruses in circulation and record numbers
In terms of numbers, this new variant has changed the situation. On November 23, while France recorded a peak of contaminations with more than 30,000 identified cases, Omicron was brought to light by South African researchers and began its meteoric progression across the globe. The first case was detected in mainland France on December 2, and less than three weeks later, supported by models, Olivier Véran predicts that “we will very likely exceed 100,000 contaminations per day by the end of the month. “. Figures below reality: on December 29, the threshold of 200,000 cases was crossed for the first time, with more than 208,000 contaminations recorded in 24 hours, and crossed daily since. The Minister of Health even evoked on Tuesday nearly 300,000 cases identified.
And if new health protocols are put in place in schools and in companies and the wearing of a mask is once again compulsory outdoors over a large part of the territory, no additional restrictions have been decreed. “The choice that has been made is to let the virus circulate,” said infectious disease specialist Eric Caumes on Sunday.
The executive prefers to focus on strengthening vaccination, with the examination since Monday in the Assembly of the bill transforming the health pass into a vaccination pass. The measure, announced on December 17 by Jean Castex, could come into force on January 15, provided that the surprise suspension of the debates on Monday evening does not lead to a delay in the schedule. In the meantime, the announcement has pushed a few handfuls of refractories to finally take the leap of vaccination. On December 29, 48,535 people received their first dose, while at the same time, the campaign for the booster dose is ongoing.
Immune “by vaccination, by infection, or both”
Record contaminations and increase in vaccine coverage: for Olivier Véran, this combo could therefore finally make it possible to achieve collective immunity. “Considering the rate of contamination in our country and elsewhere on the planet, it is probable that we have all acquired some form of immunity either by vaccination, or by infection, or both”, estimated Olivier Véran on France Inter.
A cautious optimism shared by many experts. “We are perhaps in a moment of change: until now we have had a very aggressive and transmissible virus, which has turned into a less aggressive virus, more transmissible but which gradually looks more and more like our seasonal viruses, ”summarized Professor Bruno Lina, professor of virology at the University Hospital of Lyon and member of the Scientific Council, Monday on franceinfo.
And the data available on this strain, which is the majority today, is rather reassuring. “There are three times fewer severe forms of the disease with Omicron than with Delta,” said Olivier Véran, citing the conclusions of a study carried out by the British health authorities. With this new variant, “perhaps we are witnessing the beginning of an evolution towards a more banal virus as we know others”, added Monday on BFMTV Professor Alain Fischer, the “Mr. vaccine” of the government French. “In the long term, there is hope”, and “Sars-CoV-2 will join other human seasonal coronaviruses which give us colds and tonsillitis every winter,” said epidemiologist Arnaud Fontanet this weekend. .
“We are not there yet”
But “we are not there yet, tempered the epidemiologist. New variants can be expected to emerge. But as our immunity strengthens over time, either through natural infection or with booster doses of the vaccine, their ability to give severe forms will decrease, ”he said, adding that the peak in the number of cases of Covid-19 “should peak in mid-January”.
However, faced with a virus that is certainly less virulent but highly more transmissible, the consequences could be serious at the collective level. For Professor Eric Caumes, the government has taken “a very risky bet. We are in hope, not reality, ”he continued, fearing that the outbreak of contamination would send many unvaccinated people to hospitals already“ on their knees ”. Thus, “a variant ten times more contagious, even if its pathogenicity is less, is not a benign variant”, tempered Professor Carine Lacombe, head of the infectious diseases department of Saint-Antoine hospital in Paris, Monday. on France 5.
And for the time being, it is not yet clear when this collective immunity could materialize. This could only happen in “the next year or two”, “by repeating the vaccines and keeping the mask and social distancing for the most vulnerable”, recently tabled Dr Julian Tang, virologist and professor at the university. from Leicester, cited by the British organization Science Media Center.
A “largely unpredictable” pandemic
Before claiming victory, it remains to be seen whether a new variant could once again be a game-changer. Today in the majority in France, the United Kingdom or the United States, the Omicron strain was unknown to everyone six weeks ago. In addition, the very low vaccination rate in the poorest countries of the world, like South Africa, from which two worrying variants have emerged since the start of the pandemic, calls for moderate forecasts. more enthusiastic. “It is impossible to get out of the pandemic as long as the entire planet is not vaccinated,” warns Dr Benjamin Davido, infectious disease specialist and Covid-19 crisis referent doctor at Raymond-Poincaré hospital in Garches.
“If we want to start learning the lessons of the recent past of this pandemic, let us remember that it is largely unpredictable”, underlines epidemiologist Antoine Flahault, for whom the concept of collective immunity is “purely theoretical”. And while it appears that “vaccine immunity effectively protects against severe forms of the disease”, as well as “naturally acquired immunity from a history of coronavirus infection, none of this is completely clear” . For him, all scenarios therefore remain on the table: from the most optimistic to the most pessimistic.