What happened

Shares of BioNTech (BNTX 1.52%) climbed on Friday after the biotechnology company and its pharmaceutical partner Pfizer (PFE 1.69%) released positive data related to their COVID-19 vaccine candidate. As of 3:40 p.m. EDT, BioNTech's stock was up 10% after rising as much as 15% earlier in the day. 

So what 

BioNTech and Pfizer's coronavirus vaccine candidate, BNT162b2, showed a strong ability to provoke an immune response in both young and older adults. It was also generally well tolerated; fewer than 20% of the study's participants experienced mild to moderate fever, and only a small number suffered more severe events, such as muscle and joint pain, which were temporary and manageable. 

A person is pointing to an upwardly sloping line.

BioNTech's stock rose sharply on Friday. Image source: Getty Images.

The promising results from their phase 1 study prompted BioNTech and Pfizer to advance BNT162b2 into a phase 2/3 trial. The companies intend to enroll as many as 30,000 participants in the study, of which 11,000 have already been dosed.

Now what

Should their vaccine candidate continue to demonstrate positive results, Pfizer and BioNTech hope to obtain a regulatory review for BNT162b2 as early as October. And if regulators approve the vaccine, the companies say they could supply up to 100 million doses by the end of this year and as many as 1.3 billion doses by the end of 2021.

Pfizer and BioNTech reached an agreement with the U.S. government in July, under which they'll be paid $1.95 billion in exchange for 100 million doses of the vaccine, should it prove both safe and effective.