Will all people vaccinated against Covid-19 have the right to a new injection? For the moment, only residents of nursing homes, people over 65, people at very high risk of severe disease (with co-morbidities or immunocompromised), health professionals, firefighters and relatives of immunocompromised people are eligible. to a vaccine booster. From December 1, this should also be the case for people over 50, even if the government awaits the approval of the High Authority of Health (HAS). They can nevertheless already make an appointment.
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During his speech in early November, Emmanuel Macron explained that he had requested the “scientific authorities” about “practical arrangements” of this recall campaign. These are expected in “the next days”, said the Ministry of Health, Tuesday, November 16, during a press briefing. While the United States has just given the green light to a booster dose for all adults vaccinated for at least six months (a second or third injection, as the case may be), it is highly likely that the booster dose will be also generalized very soon in France. Franceinfo explains why.
Because the effectiveness of vaccines decreases over time
Vaccines “lose some of their effectiveness after five to six months, hence the interest of a booster dose”, defended the president of the Scientific Council Covid-19, Jean-François Delfraissy, Wednesday on France Inter. “The most recent studies confirm a decrease over time in the vaccine efficacy observed in real life against infections linked to the Delta variant (from 30 to 70%)”, also recalls the HAS in an opinion issued on October 6, 2021.
In question : “The conjunction of a lower efficacy of the vaccines vis-à-vis the Delta variant and the progressive reduction of the vaccine efficacy at a distance from the scheme with two doses of vaccine”, explains the institution, based on the state of current knowledge. A study published in early November in The New England Journal of Medicine * thus shows that the efficacy of the vaccine from Pfizer and BioNTech decrease of about 6% on average every two months.
It is moreover this decreasing efficiency that justified the organization of the recall campaign for the most vulnerable populations, vaccinated from the end of December 2020. For this population, the authorities recommend the administration of a third dose six months after the last injection of the vaccine from Pfizer, Moderna or AstraZeneca.
“Although this gradual decline in protection over the six months following the primary vaccination is mainly observed in the elderly, some studies report that it is observed in all age groups (over 18 years)”, underlines the HAS. However, the vaccination of people over 50 was opened on February 19, and that of all adults without comorbidity, on May 12. The period of six months required before the injection of a booster dose is respectively over since mid-August and mid-November, for people who only needed an injection because they were contaminated with Covid-19. THEThe first double-vaccinated of these two categories are in theory likely to receive a third dose since the beginning of October for those over 50 years old, and from the beginning of January for the other adults. By counting on the same schedule as for the populations vaccinated as a priority, it would therefore be logical that the third dose be opened to them soon.
Because booster dose studies are reassuring
The current state of science testifies to the efficacy and safety of the booster dose. A study published in The Lancet *, in about 1.5 million people at the average age of 52, shows that a week after the booster dose, the effectiveness of a messenger RNA vaccine (Pfizer-BioNTech or Moderna) against the risk of hospitalization was 93% (there were 29 cases in those who received the booster dose versus 231 in the control group of the same size who had not received it). The effectiveness of the third dose was 81% against the risk of death (seven deaths in the group that had been vaccinated with a booster dose against 44 in the group that did not receive this dose).
A British study confirms these results. Two weeks after receiving a booster dose of the vaccine AstraZeneca or Pfizer-BioNTech, the protection against the onset of symptoms in the event of contamination in adults over 50 years of age was 93% and 94%, respectively, report the British authorities *.
In addition, tolerance to the vaccine seems as good as during the first injections. A study* Centers for Disease Control and Prevention (American CDC notes that of nearly 12,600 people who received a booster dose, just over 70% of those who have been vaccinated with three doses of Pfizer-BioNTech and just over 80% of those who have been vaccinated with three doses of Moderna report localized effects (arm pain, itching, etc.) or systemic (fatigue, fever, headache, etc.) within seven days of the injection, i.e. rates comparable to those observed after the second dose. Rare side effects, such as myocarditis, are not more frequent, according to the inventory drawn up by the HAS in early November.
Because the “fifth wave” is here
In addition to the lack of scientific publications on the decline in vaccine efficacy, the HAS concluded in early October that imposing a booster dose on the population was not necessary due to “the current health situation, the indicators of which are improving”. On the other hand, she stressed that “the administration of a booster dose will become[it] probably needed in the coming months “.
However, since then, the epidemic situation has deteriorated. “The fifth wave has been here since mid-October”, said the president of the Scientific Council, Wednesday on France Inter. After the decline that began at the end of the summer, contaminations (and all the indicators) are indeed on the rise, even if hospitalizations and deaths are not yet following the curve of autumn 2020. It is therefore possible that HAS may have to revise its previous recommendation in this regard.
Because France has enough doses
Could the shortage of doses be a reason to slow down the recall campaign? Not to believe the figures of the Ministry of Health. “About 25 million people are likely to receive a booster”, assured the latter, in a note of October 21 (PDF) which takes into account the criteria currently in force. Among them, about 5 million have already received their booster dose, the government spokesman assured Thursday. About 20 million people, among these first-time candidates, still need to be vaccinated.
From December 1, nearly 12 million additional people will therefore theoretically be eligible (50-65 year olds). In total, if the entire population with a complete vaccination schedule is declared eligible for a booster, 50.5 million people will have to be vaccinated, according to data from the Ministry of Health.
As of November 18, France had in stocks nearly 28.6 million doses of Pfizer-BioNTech and Moderna vaccines, according to the same source. In addition, more than 65 million doses are ordered for deliveries scheduled until July 2022, again according to figures from the ministry. There will therefore be enough to inject a booster dose to all those who wish it.
* All of these links refer to articles or content in the English language.