Faced with new variants in circulation, laboratories are working on new vaccine formulas.
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Fotoarena / Sipa USA / SIPA
The appearance in recent weeks of new variants of the coronavirus, which could make vaccines less effective, is causing great concern and could force the government to revise its vaccine strategy.
The messenger RNA vaccines would remain sufficiently effective for the time being, but that of AstraZeneca proves insufficiently protective against the South African variant.
The laboratories are already working on new formulas to offer vaccines targeting these new variants.
From the onset of Covid-19, the solution to end the pandemic has been the development of vaccines.
But only a few weeks after their arrival, the emergence of variants likely to make the vaccination less effective undermines the hope of finally regaining the life before.
A recently published study showed that the South African variant could resist the AstraZeneca-Oxford vaccine, prompting South Africa, which is facing a second wave of unprecedented magnitude, to stop vaccinating its citizens.
In France, the authorities have decided to tighten sanitary measures to prevent the spread of the South African and Brazilian variants, "which present a risk of immune and vaccine escape".
The Minister of Health in particular reported Thursday evening of "more than 300 cases of mutations suggestive of (these) the last four days in Moselle".
Faced with this risk, laboratories are already working on new formulas.
But how can the vaccine strategy be adapted to ensure the populations' immunity to these variants?
Will the entire campaign have to be restarted or could a specific vaccine booster be sufficient?
20 Minutes
takes stock.
Variable efficacy of current vaccines on variants
"We stopped vaccination with AstraZeneca [in South Africa] because this vaccine has only 22% effectiveness against the South African variant", recalled this Thursday on franceinfo Professor Alan Peter, pulmonologist in Johannesburg, Africa from South.
Regarding the Pfizer-BioNTech vaccine,
in vitro
tests
carried out at the University of Texas suggest that it remains globally effective against the English and South African variants.
For the American-German duo, these tests "have not shown the need for a new vaccine", even if it stands ready to react if this is no longer the case.
Moderna, the other messenger RNA vaccine, announced at the end of January that its vaccine also remained effective against the English and South African variants.
However, “a six-fold reduction” in antibody levels was observed against the South African variant.
But "despite this reduction", the levels "remain above what is expected as necessary to provide protection," reassures the American firm.
Still faced with variants, “AstraZeneca is less effective than RNA vaccines or the Johnson & Johnson vaccine, commented Thursday Pr Axel Khan, geneticist and president of the League against cancer, on franceinfo.
When the vaccine is not very effective [against the main strain], it becomes not very effective [against the variants].
And when the vaccine is very effective on previous strains, as is the case with RNA vaccines, it will be less effective on these new variants, but still quite effective ”.
"For now, no change in the vaccine strategy"
Faced with these results, the government is staying the course.
"For the moment, there is no change in vaccine strategy with regard to the variants", indicates the Ministry of Health, which is based on "the data provided by the laboratories [manufacturing the messenger RNA vaccines].
So at this stage, and as Olivier Véran reminded us, we continue to promote vaccination with the three vaccines ”available to date in France.
"We are in" working group "mode with the laboratories, which are themselves developing their own strategy to see how to best respond to variants, adds the side of the Ministry of the Economy and finances.
Obviously, if current vaccines work on variants, this must be the default solution ”.
The only adjustment made, "in Mayotte and Reunion, a decision was taken not to focus on AstraZeneca because of the circulation of the South African variant", specifies the Ministry of Health which, in these territories, puts " on vaccines from Pfizer and Moderna, with an increase in deliveries to Mayotte ”.
New formulas in development
But faced with these variants in circulation, moreover likely to cause reinfection, there is no question of waiting without doing anything.
Especially since the English public health agency Public Health England revealed on February 1 that it had observed the famous E484K mutation on the English variant, making it, like South African and Brazilian, potentially more resistant to certain vaccines.
And that new variants could emerge.
This is why, for the interministerial taskforce devoted to anti-Covid vaccination, “the priority is to work with manufacturers, on the ability to prepare and adapt current vaccines if necessary.
We must foresee the situation where a current vaccine does not work well enough on one or more of the variants, ”says Bercy.
For their part, most laboratories are already working on the development of new formulas.
Even if it means forging alliances.
The British firm GSK and the German CureVac announced on February 3 that they were working together on the development of a messenger RNA vaccine targeting the new variants which are currently circulating and those which may be discovered soon.
Booster, “boost” dose or universal vaccine
In practice, “several options are possible: fully develop a new vaccine that responds exclusively to the new variants.
In this case, it would be necessary to combine the old vaccine and the new one which, for its part, would intervene as a "boost" [like a booster dose], explains Bercy, who manages the supply of vaccines within the taskforce.
The other option is to develop a new vaccine which integrates the first strain - the “Wuhan strain” - and the new ones in the same vaccine, which would be bivalent or polyvalent ”.
Avenues explored by Moderna, which is working in particular on the development of a third dose for its messenger RNA vaccine.
And on the side of Pfizer-BioNTech, we are sure to be able to produce a new vaccine formula, also messenger RNA, in six weeks, by targeting the specific protein of the South African variant.
It remains to be seen whether it will be necessary to be vaccinated each year against the coronavirus and its different variants, as is the case for seasonal flu.
This is the question that scientists cannot yet answer, even though this hypothesis is considered very likely.
But hope could come from a French biotech.
Based in Lyon, the company Osivax, which already has know-how on seasonal flu, is working on the development of a universal vaccine against Covid-19.
A vaccine that targets “the internal part of the virus [more stable and less prone to mutations], indicates Alexandre Le Vert, co-founder of Osivax, at La Croix.
This makes it possible to anticipate the arrival of new variants, and even to be effective on other viruses.
The challenge is to prepare the future for future pandemics ”.
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