Coronavirus: the debate on the third dose | This is not yet planned, but some countries are already applying it for certain groups at risk

There is never two without three? The hypothesis that a third dose is necessary for all people vaccinated against covid-19 is debatable: health authorities in different parts of the world consider that it is too early to decide, but some countries are already applying it for certain fragile populations.

The debate took shape when the alliance Pfizer / BioNTech announced on July 8 that he would shortly seek authorization from a third dose in the US and Europe. According to these laboratories, the objective is to guarantee greater immune protection to people who have already been vaccinated with two doses.

“Although protection against severe cases of the disease remains high for six months, its effectiveness against symptomatic cases is expected to decline over time and the appearance of variants,” said Pfizer / BioNTech, for whom “a third dose may be needed 6 to 12 months later“of the second. Then, representatives of Pfizer defended their case before the American health authorities.

It is “prepare for the event that a recall may be required», Commented this week the medical adviser of the White House, Anthony Fauci. “But that doesn’t mean we’ll need a booster and everyone will have one. We haven’t injected enough people with the first two doses yet. At the moment, they’re not planning to do so. recommend a third dose of vaccine for the general population who have already received two.

“It is too early to confirm when a booster of the covid-19 vaccines will be needed,” they noted. European Medicines Agency (EMA) and European Center for Disease Control and Prevention (ECDC)) in a joint statement last Wednesday.

“Vaccination campaigns and studies in progress they have not yet provided sufficient data on the duration of vaccine protection, and we must take into account the spread of variants, ”say these authorities, who, nevertheless, declare themselves ready to react if knowledge evolves.

The president of the Emergency Committee of the World Health Organization (WHO), Didier Houssin, said on Thursday that “today the scientific data do not really justify“the injection of a third dose”, considering the world situation. “According to the French expert, this could even” worsen inequalities in access to vaccines “by depriving countries which already have difficulty injecting doses of doses of the first two.

Hungarian President Viktor Orban announced this Friday that from August 1 it will be possible a third vaccine for people whose second dose is at least four months old. Unlike other EU countries, where they are not allowed, Hungary makes extensive use of Chinese Sinopharm and Russian Sputnik V vaccines in its vaccination campaign.

Who would be useful

Although a consensus has not been reached on the entire vaccinated population, some countries they have already started giving a third dose to people with weakened immune systems, for example, due to an organ transplant, cancer or kidney failure.

In these patients, the immune response is poorer than in healthy people, which can potentially affect the effectiveness of the vaccination. This immune weakness can come from the health problems of these patients, but also from the drugs they take to treat them. This is the case, for example, of transplant patients, who follow treatments aimed at reducing the immune system to avoid rejection of the transplanted organ.

France and Israel have started injecting a third dose into these types of patients. “Recent data have shown that the immune response to the antibodies produced after two doses of vaccine is insufficient in severely immunocompromised people,” the French Council for the Orientation of the Vaccine Strategy said in May.

For its part, the Israeli Ministry of Health invokes “the increase in the number of cases in recent weeks and the high risk it poses to immunocompromised patients affected by serious diseases”.

Age

French President Emmanuel Macron announced last Monday that a “strengthening campaign” would begin “in early September.“For people vaccinated” in January and February. “At that time, the elderly, whether living in nursing homes or at home, were the main people vaccinated in France.

Macron relied on an opinion from the scientific council created by the government during the pandemic. We must “now anticipate a revaccination of people over 80 who reside in nursing homes (homes for the elderly) or at home,” said this council.

“The scientific data to support this proposal are still limited, but given early studies showing an earlier drop in antibody levels in this population and the possible significant impact on the healthcare system, this proposal seems reasonable. “, continues the opinion. She even advises “to anticipate that it could evolve towards a booster dose also for the youngest, depending on the health situation”.