Is a fourth dose of vaccine needed to protect against Covid-19? Even if he’World Health Organization (WHO) and the European Medicines Agency (EMA) ensure that repeated administration of booster doses “is not a long-term sustainable approach”, Lhis question is regularly asked of the government. For now, the executive remains cautious about whether or not to generalize this second reminder. “Yes [l’intérêt] is to protect the most vulnerable, we will do it and we will explain it, as we have done since the beginning of the epidemic. If, on the other hand, we see that it is not necessary, we will not do it”, argued the Minister of Health, Olivier Véran, on LCI on January 25.
For the moment, only severely immunocompromised people are concerned by the fourth dose, which is part of their complete vaccination schedule, in accordance with the opinion of November 19 issued by the Vaccine Strategy Guidance Council (COSV). Other countries like Denmark (for so-called “vulnerable” people), or Spain (for “very vulnerable” people) also made this choice.
In France, the administration of the booster dose (usually the third dose) is progressing slowly, according to data from the health authorities. But the Delta and Omicron variants are still circulating actively, contributing to maintaining a high incidence rate in many departments. However, does this health situation require the administration of a fourth generalized dose, starting with targeting “the older” ? asked the president of the Scientific Council, Jean-François Delfraissy, Tuesday on franceinfo. “We do not know”, he admitted.
Seized by the government on this issue, the Haute Health Authority (HAS) has not yet issued its conclusions. According to the president of the Technical Vaccination Commission at HAS, Elisabeth Bouvet, he is moreover not “at all sure that we will need a fourth dose” one day, she advanced to franceinfo on January 15.
“We do not currently have data that allows us to justify this measure.”
Elisabeth Bouvet, member of the HASat franceinfo
On the other hand, the COSV delivered a report on January 19 to the Minister of Health. He expressed a reservation about the usefulness of this second reminder. “We do not see very well at the moment what this fourth dose could bring, comments the president of the COSV, professor Alain Fischer, in The world (paid item). It increases the level of antibodies. But with what real intensity, what effect on serious forms and for what duration, we do not know. As for the protection vis-à-vis the infection by Omicron, the recall improves it, but in a limited way. So we don’t expect wonders from the fourth dose.”
This reservation is also explained by the weakness of the scientific literature on the benefits of an extended fourth dose. And this, even if a country like Israel has opened, since the beginning of the year, this additional sting to pover 60, caregivers, in addition to immunocompromised people.
“It is open” to the most fragile, but “it is not necessarily recommended (…). We do not have enough data regarding the effectiveness and safety of this fourth dose”, admitted Cyrille Cohen, immunologist at Bar-Ilan University in Tel Aviv (Israel), to franceinfo on January 3. If this fourth dose allow “to increase the level of antibodies”, she does not offer “only a partial defense against the virus”, said Professor Gili Regev-Yochay, who is leading a six-month Israeli study on the subject, in a statement released by Sheba Hospital on January 17.
If the effectiveness of a fourth generalized dose still awaits scientific validation, the vials containing the product must also be available in sufficient quantity. On the side of the Pfizer laboratory, the executive chairman, Albert Bourla, specified, in an interview on BFMTV on January 17, that“in March, [ils] will have data on the efficacy of a fourth dose”, while affirming that his laboratory will be able to offer a large volume of doses when the time comes.
As for the CEO of Moderna, the French Stéphane Bancel, he is convinced of the need for a fourth dose. And he estimates that his company, based in the United States, will be able to market an annual booster dose against both Covid-19, influenza and RSV (respiratory syncytial virus, infecting the lungs and respiratory tract) “in the best case, in the fall of 2023″. “We are convinced that it is possible in some countries next year”, he specified.