The European Commission said today it had entered final stage talks with BioNTech-Pfizer to purchase up to 300 million doses of a potential vaccine against Covid-19. 

This is the sixth potential vaccine for which the European Union executive has struck or plans to strike an advance purchase agreement. 

The envisaged contract with Germany's BioNTech and US-based Pfizer would lead to an initial purchase of 200 million doses, with an option to buy a further 100 million, the Commission said after the conclusion of exploratory talks. 

All EU members would have the possibility to buy the vaccine and could donate to poorer nations or redirect to other European countries. 

EU supply would be produced by BioNTech's sites in Germany and Pfizer's manufacturing site in Belgium, with deliveries starting by the end of the year, the companies said in a statement. 

They added they were on track to seek regulatory review of their potential vaccine in October and, subject to approval, plan to supply up to 100 million doses worldwide by the end of 2020 and about 1.3 billion doses by the end of 2021. 

The proposed agreement with the European Commission would be the largest initial order of doses for Pfizer and BioNTech to date, they said. 

The companies are developing a new variety of vaccine based on messenger RNA (mRNA), which makes the human body create viral proteins, prompting the immune system to produce a defensive response. 

The Commission reached a first agreement last month with AstraZeneca for at least 300 million doses of its potential vaccine, mirroring moves by the US and other wealthy states to secure stock of effective Covid-19 vaccines. 

It has also concluded exploratory talks with Sanofi-GSK, Johnson & Johnson, CureVac and Moderna to buy upfront their potential Covid-19 vaccines and is in discussions with other manufacturers.