BRUSSELS - The European Commission said on Thursday it had sealed a supply deal with Johnson & Johnson for the supply of its potential COVID-19 vaccine for up to 400 million people.

This is the third advance purchase contract signed by the EU with makers of COVID-19 vaccines after deals with AstraZeneca and Sanofi.

Under the terms of the deal, the 27 European Union states will be able to order up to 400 million courses of the potential vaccine after it is authorised as safe and effective by the EU medicine regulator.

"The contract allows member states to purchase vaccines for 200 million people. They will also have the possibility to purchase vaccines for an additional 200 million people," the EU commission said in a statement.

To secure the vaccines, the EU made a downpayment to Johnson & Johnson. The amount paid has not been disclosed.

(Reporting by Francesco Guarascio @fraguarascio; Editing by Jason Neely and Alison Williams) ((Francesco.Guarascio@thomsonreuters.com; +32 2 287 68 17;))