The European Union’s (EU) executive arm on Thursday finalised a third vaccine contract with Pfizer and BioNTech through 2023 for an additional 1.8 billion doses of their Covid-19 shot.

The European commission said the deal, which was agreed on behalf of all 27 EU countries earlier this month, will allow the buying of 900 million doses of the current shots and of a serum adapted to the virus’ variants, with an option to purchase an extra 900 million shots.