They are eagerly awaited in order to launch the recall campaigns. The new vaccines against Covid, which should target more particularly the Omicron variant and its sub-variants, have just been approved by several countries. Their next marketing should make it possible to counter the probable resurgence of the epidemic this fall and this winter. “We must be ready to face another winter with Covid-19,” warned European Health Commissioner Stella Kyriakides. Franceinfo takes stock. 1What is this new generation of vaccines? The American laboratories Moderna and Pfizer have again used so-called messenger RNA technology. It is simply an update of the original vaccines Comirnaty from Pfizer-BioNTech and Spikevax from Moderna. They fight both against the original strain of Sars-CoV-2, but also against Omicron, which is largely dominant today. These new vaccines are intended for individuals over the age of 12 who have already been vaccinated against Covid-19. The vaccines currently in circulation have in fact proved to be less effective against the variants that have appeared over time. Other laboratories are in line to release their vaccine. The Spanish pharmaceutical firm Hipra, which has signed a contract with the European Commission to supply up to 250 million doses, is awaiting approval by the European regulator. The French Sanofi is developing a vaccine used as a booster dose and which must also be effective on the sub-variants of Omicron. 2Do these new vaccines work on all Omicron subvariants? The new vaccines currently target the Omicron BA.1 subvariant. However, things should change quickly. A new Pfizer vaccine targeting the contagious BA.4 and BA.5 lineages of the Omicron variant, which have emerged in recent months as the dominant strains in the world, should be authorized in mid-September. A similar vaccine from Moderna is also in the works. 3Which countries allow them? United States, United Kingdom, Canada… Several countries have already approved the use of these new vaccines, in different forms. In the United States, the Centers for Disease Prevention and Control (CDC), the country’s main health agency, recommended them on Thursday, September 1, which makes their use possible, perhaps as early as next week. The day before, the American Medicines Agency (FDA) had authorized the versions of the two laboratories. Canadian health authorities also approved the new version of Moderna’s vaccine on September 1, with the aim of quickly starting a new recall campaign. Canada has already purchased 12 million doses of this vaccine and hopes to be able to start vaccination at the end of September, explained Dr. Howard Njoo, deputy chief federal public health officer. For its part, the British drug regulator announced on Saturday, September 3, that it had approved the new generation of the Pfizer-BioNTech vaccine. In mid-August, the UK became the first country to authorize Moderna’s new vaccine. And for the EU? The European medicines regulator approved, on September 1, the new vaccines Pfizer-BioNTech and Moderna. “Today’s positive opinions from the European Medicines Agency on the first two variant-matched mRNA vaccines, from BioNTech-Pfizer and Moderna, are important to protect Europeans against the likely risk of waves of autumn and winter infections. “, said the European Commissioner for Health, Stella Kyriakides. 4When will they be available in France? For the moment, no precise date of marketing of these new vaccines in France has been communicated. Nevertheless, the objective remains that they be used during the vaccination recall campaign, which, according to the Scientific Council in its opinion of July 19, “could be open to people under 60 from the autumn”. Currently, those eligible for a fourth dose are those over 60 whose last injection was more than six months ago, pregnant women and all those at risk. 5Are they really more effective? The results published by the laboratories are encouraging. According to Moderna, antibodies against Omicron, for example, increased 8-fold from their level before injection, compared to only a 4-fold increase with a booster using the initial vaccine. “The usefulness of these new vaccines seems relatively obvious. If we compare to what we do, for example, for the flu vaccine, when the flu virus mutates and changes, we change the vaccine against this virus . We are in the same context”, explains on franceinfo the immunologist Jean-Daniel Lelièvre, head of the infectious diseases department of the Henri-Mondor hospital in Créteil, member of the Technical Commission for Vaccinations of the High Authority for Health ( HAS) and expert for the WHO. “We saw these new variants arrive very quickly. We have to adapt to these new variants.” Jean-Daniel Lelièvre, immunologist at franceinfo “The techniques of messenger RNA make it possible very quickly to have new vaccines”, again greets the specialist.