With the arrival of the Omicron variant and the fifth wave of the pandemic in France, the question legitimately arises of the administration of a fourth dose of vaccine, or second booster dose. Pending a scientific consensus, the Advisory Council for the Vaccine Strategy has expressed reservations.
In a notice dated January 19 Last, the COSV, chaired by Alain Fischer, gave its analysis as to the relevance of a second booster dose in the fight against the epidemic. The experts notably cited a clinical trial launched in Israel a few weeks ago, which found that many people infected with the Omicron variant had nevertheless received a fourth dose of vaccine, which can presume a lesser effectiveness of the booster to protect against infection with this variant.
The available scientific data also indicate that an infection with the Omicron variant “could provide an ‘immune dividend’ offering new protection against future infections”, and in particular against “future variants”. Some other countries have already implemented the fourth dose, but almost exclusively for vulnerable people. In France, it is also already authorized for severely immunocompromised patients.
Protection against severe forms lasts over time
The COSV also underlined that while studies show that protection against the symptomatic forms of the disease decreases ten weeks after the booster vaccination, “no consistent piece of information suggests that the protection against the onset of severe forms conferred by a vaccine booster decreases over time.”
Given these elements, “the COSV considers that the available data do not currently call for the implementation of a second vaccination booster, although the question is made legitimate by the current context of strong circulation of the virus”. “Such a measure could be interpreted as a signal of ineffectiveness of vaccination by public opinion and thus induce a risk of disengagement with regard to vaccination perceived as too frequent”, he added.
Caution on the side of the French authorities
The High Authority of Health, seized by the government, must still rule on the question. Questioned this Tuesday, January 25 on the question, the Minister of Health, Olivier Véran, affirmed that if the fourth injection makes it possible to “protect the most fragile we will do it and we will explain as we have done since the start of the epidemic. If, on the other hand, we see that it is not necessary, we will not do it.
For its part, the World Health Organization (WHO) had already warned against the strategy which would aim to administer a booster dose regularly. “No country will be able to get out of the pandemic with booster doses. (…) Indiscriminate booster programs have every chance of prolonging the pandemic, rather than ending it, by diverting available doses to countries that already have high vaccination rates, thus giving the virus more opportunities to spread and mutate,” said its director Tedros Adhanom Ghebreyesus a few days before Christmas.