Are we going to have to combine different doses of vaccine to be better protected?
The administration of a booster dose of a vaccine against Covid-19 different from that received during the first injections could elicit a stronger immune response than a booster with the same vaccine, the European regulator stressed Thursday.
The Hague-based European Medicines Agency (EMA) said it was studying data to decide whether it would align with a decision by the US Medicines Agency (FDA) which cleared the injection on Wednesday. a different vaccine for the booster dose than that used for the first doses.
Pfizer-BioNTech, Moderna, Johnson & Johnson and AstraZeneca vaccines are currently authorized in the European Union.
The EMA has approved the principle of a third dose of Pfizer / BioNTech for those over 18, leaving the States with a more precise choice of eligible populations.
"We are seeing some promising results in studies which confirm that this approach elicits, with certain combinations of vaccines, a stronger immune response than when the same vaccine is used for an additional injection," Marco said at a press conference. Cavaleri, responsible for vaccine strategy at the EMA.
"A really strong immune response"
Several countries have approved a booster dose to boost the immunity of those vaccinated, which appears to wane after several months, despite usually using the same type of vaccine.
A study released in the United States last week showed that people who received the Johnson & Johnson vaccine, which like AstraZeneca uses classic viral vector technology, appeared to be better protected by a booster dose of an RNA vaccine. messenger like Pfizer or Moderna.
Booster dose messenger RNA vaccines "seem to work much better" in boosting immune defenses "and are able to elicit a really strong immune response," Cavaleri said.
The EMA is also due to decide on October 25 whether to approve boosters with the Moderna vaccine, he added.
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A study released Thursday by the Pfizer / BioNTech alliance indicated that a third dose of their vaccine is 95.6% effective against symptomatic forms of the disease.
The EMA expects to decide within the next two months whether to approve the Pfizer / BioNTech vaccine for children aged 5 to 11, after the two laboratories submitted their data to it last week.
The Agency is also due to examine next week an anti-Covid drug for oral administration produced by the US pharmaceutical company Merck, said Marco Cavaleri.
