The European Union's medicines regulator will decide on Monday whether to approve Pfizer's Covid-19 booster vaccine, but it is unlikely to give precise guidance on who should receive it, according to an internal document and two officials.
If the European Medicines Agency (EMA) gives its backing for the jab, the EU would join the United States, the UK and Israel which have already received the green light to deploy boosters, even though there is no consensus among scientists that they are necessary.
"On 4 October the EMA will deliver an opinion on the need for Pfizer boosters for the general population," the EMA's head Emer Cooke told EU lawmakers in an internal meeting yesterday, according to minutes of the discussion seen by Reuters.
The agency was not immediately available for a comment.
It has publicly said it would decide on Pfizer's booster at the start of October, but has never given a precise date.
More than a dozen EU countries have already started administering boosters without official EMA backing.
Official approval will provide legal protection to those countries and may spur others to launch a booster programme to fight the more infectious Delta variant of the coronavirus during the winter months.
Two EU officials familiar with the EMA's decision-making processes said next week's decision will focus on the booster's safety and effectiveness, and will be broad in scope, meaning that it will not indicate precisely which age or risk groups should receive it.
That would be in line with the EMA's decisions on vaccine boosters for other diseases, such as tetanus.
The approach would also be consistent with its earlier decisions in the pandemic - for instance it largely left it up to member states to decide whether to restrict vaccines in the face of potential side effects.
The broad guidance would allow states to tailor the use of boosters to their national needs, without risking administering them beyond the instructions authorised by the agency, which would increase their legal risks.
In August, the EMA said there was not enough data to recommend using boosters, and the World Health Organization has called for a halt to boosters until more people around the world have been vaccinated.
"There is no need of boosters for the general population, but there is some waning effect, especially for the elderly," Ms Cooke told EU legislators, according to minutes of the internal meeting.
The wide guidance could amplify differences across EU states. Who gets a booster is already fragmented. In Austria, Hungary and the Czech Republic, authorities are aiming for wider roll-outs, whereas in other states only some more vulnerable people would receive boosters.
The European Commission has repeatedly warned that different national policies on vaccines can increase hesitancy.
The EMA's broad approach would also differ from other major Western countries.
The US Food and Drug Administration (FDA) last week recommended the Pfizer booster for those aged 65 and older, all people at high risk of severe disease, and others who are regularly exposed to the virus.
In the UK, boosters are being given to all adults aged 50 or over, healthcare workers, and all those at high risk from Covid-19 or in close contact with immuno-suppressed individuals.
Scientists are divided over whether boosters are needed, because it is not yet completely clear how long protection lasts in people who have been fully vaccinated, the European Centre for Disease Prevention and Control (ECDC) said.
However, EU states have already bought additional vaccines for boosters.
They agreed in May to buy at least 900 million doses of the Pfizer/BioNTech vaccine. This came after the EU had already secured more than enough shots for its entire population from Pfizer and other vaccine makers.
Under the contract, EU governments are required to buy the 900 million shots mostly from next year, and could order another 900 million until 2023.
Given that nearly 75% of the EU's adult population has already been fully vaccinated, most of the additional Pfizer doses would likely be needed only if administered as boosters.
An alternative would be to donate or sell them to poorer nations who have not yet got enough doses. Some of the vaccines could also be deployed on children or be used against potential new variants. Pfizer has agreed to sell the EU modified shots if needed.
But the decision on when a new variant may be predominant and whether the existing vaccine is not effective against it requires a complex procedure which makes it difficult to force Pfizer to provide an updated version, two people familiar with the contract told Reuters.
Pfizer had no comment on the contract with the EU but the company's boss Albert Bourla has said that it can develop in less than 100 days updated versions of its Covid-19 vaccine, if new variants emerged.