This is a welcome boost for people vulnerable to Covid-19. The coronavirus vaccination campaign has been brought forward to October 2, as announced by Minister of Health Aurélien Rousseau. Its start was initially scheduled for October 17, at the same time as the seasonal flu vaccination campaign, to allow the administration of both injections on the same day. The priority targeted population is estimated between 12 and 18 million people. Why hurry? Should we expect difficult months ahead? Will the new vaccines be effective?

Are the new variants more to be feared than the previous ones?

It is not the resumption of the epidemic since mid-summer that worries the experts. What concerns them are the new variants, which are more easily able to thwart our immune defenses, acquired laboriously since the start of the pandemic in 2020, through infections and vaccine boosters. “This ability to escape immune system is what bothers us the most,” explains Brigitte Autran, president of the Committee for Monitoring and Anticipation of Health Risks (Covars). The immune response that we have built does not protect well against variants that are currently circulating. Particularly against the latest additions, EG.5.1 (Eris) and BA.2.86 (Pirola), the most worrying to date. »

Currently, most people hospitalized or in intensive care for Covid-19 are, as expected, fragile patients – elderly or suffering from chronic pathologies – whose immune responses are particularly insufficient to current variants. “In this context, as the new vaccines are available, there is no reason to wait any longer,” insists Brigitte Autran, stressing that, in many neighboring countries such as Belgium, Germany, the United Kingdom, the campaigns are already launched.

They are well adapted to the variants in circulation. All were developed from the XBB.1.5 strain, predominant last spring and therefore recommended as a target by the WHO. So far, most vaccines used targeted either the historical strain (Wuhan strain) or Omicron-derived strains.

The first of the new vaccines already available is that of BioNTech-Pfizer, based on messenger RNA. That of Moderna, using the same technology, should also arrive very quickly because it received European marketing authorization (AMM) on September 15. The third vaccine, the one based on proteins and developed by Novavax, is still being evaluated.

We will have to wait several weeks before having precise percentages on effectiveness in “real life”. But we know that the vaccines used in previous years provided 85% to 95% protection against severe forms. “We are entering a bit of a new era. Initially, vaccines were effective in limiting infections and transmission. These new vaccines are intended to protect against serious forms and limit the risk of going to hospital, but they will not be extremely effective in preventing the circulation of the virus. This is why we do not insist much on vaccinating younger or healthy people who defend themselves very well against severe forms with what remains of their immune defenses,” explains the immunologist.

“All those who wish,” insists Brigitte Autran. “But those who concern us are really the people at risk of serious forms, therefore the elderly, people in nursing homes, those who have risk factors for either immunosuppression or cardiorespiratory pathologies, or even those who are overweight. important. They are the ones who risk, without this reminder, going to intensive care and possibly dying. » The HAS indication in June has not changed. What should we do for children who were not vaccinated at all during the first waves of Covid-19 but who, in the overwhelming majority, experienced an episode of infection? “It’s not an emergency,” emphasizes Brigitte Autran.