Add multinational giant Pfizer to the list of pharmaceutical companies that have seen their shares jump on a dose of good, coronavirus-related news.

Pfizer’s stock was up more than 5% on Wednesday afternoon, after the company reported positive results in an early trial for a potential COVID-19 vaccine.

The trial, which Pfizer is conducting alongside German biopharma firm BioNTech, found that the most advanced of four vaccine candidates being vetted “is able to produce neutralizing antibody responses in humans” against the coronavirus, according to BioNTech CEO Ugur Sahin.

Kathrin Jansen, Pfizer’s head of vaccine research and development, said the company is “encouraged by the clinical data” and is planning to publish the clinical data “in a peer-reviewed journal as quickly as possible.”

While some of the trial subjects experienced side effects, including “low-grade fever,” after receiving doses of the vaccine, Pfizer said that “no serious adverse events were reported” as a result of the trial.

The positive news could lead to a larger trial for the vaccine potentially involving up to 30,000 subjects, Pfizer and BioNTech said. That trial could begin by late July, pending regulatory approval. Eventually, the pharmaceuticals would be prepared to manufacture “up to 100 million doses of the vaccine by the end of 2020 and potentially more than 1.2 billion doses by the end of 2021,” they said.

Pfizer and BioNTech are far from the only pharma players currently working on a preventative vaccine for COVID-19. More than a dozen different potential vaccines are either currently in human trials or expected to begin them soon.

Among the most advanced is a vaccine being developed by Moderna Therapeutics. Like Pfizer, Cambridge, Mass.-based Moderna saw its stock soar after announcing positive early-stage trial results in mid-May.