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Omicron variant: current vaccines still effective, according to WHO

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The variants of the coronavirus follow one another and in turn raise the same questions. After Delta, Omicron also questions the effectiveness of vaccines against it. On this subject Michael Ryan, Irish epidemiologist and head of emergencies at the World Health Organization (WHO), was rather reassuring, even if gray areas persist.

This Tuesday, December 7, he estimated that “there is no reason to doubt” that the current vaccines protect patients infected with the Omicron variant against severe forms of Covid-19. The various existing sera “have demonstrated their power against all variants so far, in terms of the severity of the disease and hospitalization,” said the expert to AFP. So why would Omicron be an exception?

In the current state of knowledge, we are entitled to think that “the vaccine seems to hold up in terms of protection”. But the Irish epidemiologist, who has been working in the fight against Covid-19 since its detection at the end of 2019, concedes a certain singularity of Omicron. The variant is distinguished by a very high number of mutations in the spike protein, the one that allows the virus to attach itself to cells before invading them to multiply.

This specificity could indicate a reduced effectiveness of the vaccines but “it is highly improbable” that the variant can completely escape the protection conferred by the injections, judge Michael Ryan. “The preliminary data we have from South Africa does not show that we are losing efficiency of catastrophic proportions. In fact, it is even the opposite at the moment ”.

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If we are to believe the Pfizer and BioNTech laboratories, the serum they designed is “still effective” against Omicron, but the latter is “probably not sufficiently neutralized after two doses”. With three injections, these companies promise “a level of neutralizing antibodies against Omicron similar to that observed after two” doses for the other variants. At the same time, the laboratories announce “to continue the development of a specific vaccine” for this new mutation of the coronavirus, which could be “available by March in case an adaptation is necessary”.

Insisting on the fact that Omicron was detected very recently, on November 24, Michael Ryan recalls that studies on him are only just beginning. “We are at the very beginning, we must be very careful in our way of analyzing,” he warns. It is probable that Omicron is more contagious but, for this official of the WHO, it is not very surprising: “When a new variant appears, it tends to be more transmissible, because it is in competition. with the previous variants, ”he explains.

It is also possible that Omicron is currently spreading rapidly in South Africa because it “exploits a decline in transmission from Delta”, qualifies the expert. There is some evidence to suggest that the newcomer is causing ‘more frequent re-infections […] than with the previous waves or variants ”. But for Michael Ryan, this does not call into question the anti-Covid vaccines which, he recalls, were designed to protect the most serious forms of the disease and not necessarily against those which are more benign.

No increased severity observed so far

Anyway, the discovery of this new variant has raised some concerns, especially in Europe where the fifth wave linked to Delta is still underway. On Tuesday, December 7, the European Commission called on the Twenty-Seven to coordinate to establish coherent traffic restrictions and fight against the outbreak of Covid-19. The body also encouraged them to speed up the vaccination campaign when, at the same time, the WHO advised to strengthen the protection of children, currently the most affected age group.

But more than the speed at which the variant spreads, what interests the researchers above all is whether Omicron induces an increase in the severity of the symptoms. However, nothing indicates it for the moment, according to “the general behavior observed so far in this new variant”. Michael Ryan even adds: “In fact, some places in southern Africa report milder symptoms.”

On this point, he agrees with Anthony Fauci, an American scientist, for whom it is “almost certain” that this new variant does not cause more serious cases than Delta. If he considers it “clearly highly transmissible”, this White House adviser also evokes the possibility, according to “some signs”, that Omicron is less dangerous than Delta. He advises to wait “two weeks at least” to have more elements at this level.

Since “the virus has not changed in nature”, Michael Ryan recommends fighting it with the tools that have already proven their worth. According to him, vaccines are “the best weapon” we have. Faced with the dreaded Omicron “the rules of the game remain the same”: wearing a mask, ventilation and social distancing.

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