By Dave Sebastian

Pfizer Inc. and BioNTech SE said two of their four Covid-19 investigational vaccine candidates got fast-track designation from the U.S. Food and Drug Administration that will expedite review.

The companies said the candidates, BNT162b1 and BNT 162b2, are the most advanced among the BNT162 program that is in early clinical studies in the U.S. and Germany.

In premarket trading Monday, Pfizer shares rose 1.5% to $34.34, and BioNTech's ADRs were up 5.1% at $73.99.

Researchers earlier this month said Pfizer and BioNTech's vaccine candidate showed promising signs of working in an early-stage study. Healthy adult volunteers given the vaccine candidate had higher levels of antibodies four weeks after being vaccinated and seven days after getting a second dose, compared with the antibody levels in recovered Covid-19 patients who didn't get the shots, the researchers reported.

The companies said they expect a later-stage study as soon as later this month and anticipate enrolling up to 30,000 participants. If the studies are successful and the vaccine gets regulatory approval, Pfizer and BioNTech said they expect to make up to 100 million doses by the end of the year and more than 1.2 billion doses by the end of 2021.

The companies expect early data from the German study of BNT162b1 to be released this month.

About 13 million people worldwide have contracted Covid-19, and about 4.4% of those people have died, according to data collected by Johns Hopkins University.

Write to Dave Sebastian at dave.sebastian@wsj.com