Two experimental coronavirus vaccines jointly developed by German biotech firm BioNTech and U.S. pharmaceutical giant Pfizer have received 'fast track' designation from the U.S. drug regulator, the companies said on Monday.

The candidates, BNT162b1 and BNT162b2, are the most advanced of the at least four vaccines being assessed by the companies in ongoing trials in the United States and Germany.

Pfizer's shares were up about 2% and U.S.-listed shares of BioNTech were up about 6% before the bell.

Earlier this month, the companies said BNT162b1 showed potential against the virus and was found to be well tolerated in early-stage human trials. 

Early data from the German trial of BNT162b1 are expected to be released in July, the companies said.

If the ongoing studies are successful, and the vaccine candidate receives regulatory approval, the companies said they expect to make up to 100 million doses by the end of this year and potentially more than 1.2 billion doses by 2021-end.

The companies said they expect to begin a large trial with up to 30,000 participants as soon as later this month, if they receive regulatory approval.

The fast track status by the Food and Drug Administration is granted to speed up the review of new drugs and vaccines that show the potential to address unmet medical needs.

(Reporting by Manas Mishra and Manojna Maddipatla in Bengaluru; Editing by Shinjini Ganguli) ((Manas.Mishra@thomsonreuters.com; www.twitter.com/Manasmishra24; within U.S. +1 646 223 8780, outside U.S. +91 806749 2709;))