What happened

Shares of Ocugen (OCGN 3.49%) climbed on Wednesday after the biopharmaceutical company's partner, Bharat Biotech, released promising results from a phase 3 trial of its COVID-19 vaccine candidate, Covaxin. 

As of 3 p.m. EDT, Ocugen's stock price was up more than 12% after rising as much as 22.5% earlier in the day.

So what 

A second interim analysis of a phase 3 study with 25,800 participants showed Covaxin to have efficacy against mild, moderate, and severe COVID-19 of 78%. Against severe COVID-19 alone, that figure came in at 100%.

"We believe that Covaxin can help change the course of this pandemic by preventing severe COVID-19 disease including hospitalizations by 100% as well as significantly limit the spread of asymptomatic COVID-19 infections based on efficacy shown to date," Ocugen CEO Dr. Shankar Musunuri said in a press release.

A person is pointing to a digital stock chart that rises, then falls, then rises again.

Investors bid up Ocugen's stock price on Wednesday. Image source: Getty Images.

Ocugen reached an agreement with India-based vaccine developer Bharat Biotech in February to commercialize Covaxin in the U.S., should it receive regulatory authorization. The deal gives Ocugen a 45% share of any potential profits, with Bharat Biotech receiving the remaining share. 

"We are dedicated to being a part of the solution to save lives from COVID-19 by bringing Covaxin to the U.S. market," Musunuri said.

Now what

Covaxin's efficacy is notable considering that multiple coronavirus variants were circulating at the time of the trial. Still, it remains to be seen whether there will be enough demand for the vaccine in the U.S., even if it receives Emergency Use Authorization.

Pfizer's and Moderna's vaccines have demonstrated efficacy of roughly 95%, though it's not an apples-to-apples comparison, since their clinical trials were conducted when coronavirus mutations were less prevalent. Still, Ocugen may find it challenging to wrestle away market share from these vaccine leaders in the U.S.