By Emilio Parodi and Francesco Guarascio

BRUSSELS (Reuters) – The European Medicines Agency (EMA) expects to decide in early October on the possible use of a booster dose of the Pfizer-BioNTech COVID-19 vaccine, a source with direct knowledge of the matter told Reuters.

It will be the EU drugs regulator’s first decision on boosters, the source said, after the U.S. Food and Drug Administration on Wednesday authorized a third dose of Pfizer (NYSE:) for those 65 and older, all people at high risk of severe disease, and others who are regularly exposed to the virus.

The source stated that the EMA will make a decision about the third Pfizer dose in October. He declined to name the reason for the sensitive nature of the issue.

Pfizer refused to comment while BioNTech wasn’t immediately available.

Pfizer and BioNTech submitted data to the EU regulator on September 6. The EU regulator announced that they had started evaluating these data for a booster dosage. This will be six months from the last dose. It is intended to give this dose to people who are 16 or older.

Moderna (NASDAQ:) is also expected to submit data to the EMA this month on its booster dose, an EU document said.

ECDC, European Centre for Disease Prevention and Control stated in an opinion published in September and republished in the EMA that there is no need for booster doses for all fully vaccinated persons in the population.

It also stated that booster doses for those with severely compromised immune systems should be taken into consideration as part of primary vaccination.

Many EU member states are already considering administering a booster dose, despite higher legal risks and lack of a formal decision by the EMA.

Pfizer, BioNTech and the EU have signed three contracts totalling 2.4 billion doses.

At least 900,000,000 doses of vaccines will be available under the latest contract. This is sufficient to provide boosters if necessary or to combat new strains of virus.

The EU has secured a large supply of vaccines from many manufacturers, with over 70% of its adult population already fully vaccinated.

ECDC stated that crucial information on safety and necessity of boosters is still lacking. This may be due to the fact that vaccines do not protect for as long as it takes.