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While France is starting a campaign for a third dose of vaccine against Covid-19 in nursing homes, some countries have already generalized this recall to the entire population in order to fight against the new variants. A policy that divides in the current health context, while large disparities in access to the vaccine persist across the world.
A new vaccination campaign began in France, Monday, September 13, in residential establishments for the elderly, as the country is going through a fourth wave of the Covid-19 epidemic. Faced with the progression of the Delta variant, both more contagious and more resistant to the vaccine, the High Authority of Health (HAS) had recommended, in its report of August 24, a vaccination booster for fragile people, as well as those over 60 years from mid-September.
If the government has not yet given any indication on a possible generalization of this third dose to the entire population, other countries such as Israel or Hungary have already taken the plunge, sparking lively debates then. that access to the vaccine remains very unequal across the world.
Since the discovery of the initial strain of Sars-CoV-2 in December 2019 in the city of Wuhan, several thousand Covid-19 mutations have been spotted by scientists around the world. If the overwhelming majority of these variants do not present any particular difficulties, certain mutations oppose a form of resistance to vaccines against the disease. This is the case of the Delta variant, known as “Indian”, which is now the majority in France.
“When we catch Covid-19 or get vaccinated, we develop antibodies against the disease. This protection lasts a few months then gradually decreases. The third dose increases the dose of antibodies and therefore increases the level of protection “, explains Professor Jean-Daniel Lelièvre, head of the immunology and infectious diseases department at Henri-Mondor hospital in Créteil. “This reminder is all the more important in the face of forms of the variant like Delta which are particularly contagious. The difficulty is knowing which audience to give it to and when so that it is most effective.”
At the end of August, Israel launched a large third-dose vaccination campaign, open to all citizens aged 12 and over. The country which had, in July, allowed over 60 years to receive the booster, has since administered a third dose of vaccine to several thousand of its citizens. If the United States is preparing to launch a similar campaign, open to all adults from September 20, the subject arouses more reluctance on the old continent. The European Medicines Agency (EMA), which is currently studying this possibility, has not yet given its opinion, but has indicated that a recall for the general population is not an emergency at present.
“In vaccinated subjects, the minimum duration of immunity is now evaluated at around six months”, explains Gérard Dubois, professor of public health and member of the Academy of Medicine, “We also know that once past This period, the elderly lose these antibodies more quickly, they must therefore be revaccinated as a priority. For younger people without co-morbidities, the urgency is not the same and there is debate. “
At the end of August, the European Commission had specified that in the absence of a decision, the administration of the third dose would come under “the responsibility of the States”. If several countries including France, Germany, Sweden or even Austria, now wish to vaccinate their population at risk with a third dose, Hungary is the only country in the bloc to have opened the booster vaccination campaign to the general population.
- A purely national question ?
In addition to the debate on the relevance of the booster campaign, the administration of the third dose raises ethical questions, while strong inequalities in access to the vaccine persist across the world. On the African continent in particular, the level of vaccination of populations remains very low: only 3% of people have completed their vaccination course. A delay due in particular to the slowness of the Covax program, set up to facilitate access to vaccines for developing countries. According to the WHO, a total of 165 million doses have so far been delivered to the continent, for a population of approximately 1.38 billion.
“At the level of a country, it is conceivable that the health authorities offer a third dose to the populations most at risk to avoid hospital overflow. On the other hand, vaccinating a whole population with a third dose while entire countries do not ‘not having access to the first is clearly not a wise health strategy, “said Jean-Daniel Lelièvre.
“Who says pandemic says global strategy, and a strictly national health policy cannot defeat the virus”, emphasizes Gérard Dubois. “However, it is true that the hospital, medical and economic implications are such that leaders are obliged to do everything possible to protect their populations. This is all the more the case since many of them have been very criticized for their lack of anticipation in this crisis. Today the question of the third dose is a very difficult political calculation. “
In early August, the World Health Organization (WHO) called for a moratorium on the use of third doses until the end of September to reduce the abysmal gap in access to the vaccine between rich and poor countries. A month later, its chief executive, Tedros Adhanom Ghebreyesus, rants: “I will not remain silent when the companies and countries that control the global vaccine supply think that the world’s poor must be content with the leftovers.” US President Joe Biden prefers to focus on the 114 million doses sent to developing countries, making the United States the world’s largest donor of Covid-19 vaccines.