What happened

Shares of German clinical-stage biotech BioNTech (NASDAQ:BNTX) are up 26.6% in pre-market trading on Monday as of 9:17 a.m. EST, which suggests they're going to skyrocket during today's regular trading session.

While today's action is naturally overshadowing BioNTech stock's past performance, it's worth mentioning the stock gained 23.3% last month, according to data from S&P Global Market Intelligence. For context, the S&P 500 (including dividends) fell 2.7% in October.

Small vial with "Coronavirus vaccine" written on it and a stethoscope sitting on a flat white surface.

Image source: Getty Images.

So what

October performance

We can attribute BioNTech stock's robust performance last month largely to continued investor enthusiasm about the company's progress in developing a COVID-19 vaccine with its partner, pharmaceutical giant Pfizer (NYSE:PFE). The two teamed up in March.

Monday, Nov. 9, performance

Investors who bet on BioNTech are looking like their optimism was well placed. Its shares are exploding higher in Monday's pre-market session because today at 6:45 a.m. EST, the company and Pfizer announced terrific news about their COVID-19 messenger RNA (mRNA)-based vaccine candidate, BNT162b2: It was more than 90% effective in preventing the disease caused by the novel coronavirus based on initial data from a large-scale phase 3 clinical study. Moreover, they said they have found no serious safety concerns.

These results put the two partners at the front of the race to develop a vaccine to help halt the pandemic, which has killed more than 1.2 million people globally, including more than 238,000 people in the United States. 

Pfizer and BioNTech said they plan to seek Emergency Use Authorization (EUA) from the U.S. Food and Drug Administration (FDA) soon after a required safety milestone is achieved, which they expect to occur in the third week of November.

For context, a higher than 90% efficacy rate is probably much better than many experts were expecting for the initial round of vaccine candidates. The FDA has said it would give EUA to successful vaccine candidates that were at least 50% effective.

One caution, however: We don't know how long the partners' vaccine provides protection against COVID-19. The above stated efficacy rate was achieved at seven days after the second of the two-dose vaccination, or 28 days after the first dose. The two companies said the "final vaccine efficacy percentage may vary."

Now what

Investors -- and the world -- should know more soon, but it's certainly looking like BioNTech and Pfizer have developed what will soon be the first FDA-approved COVID-19 vaccine.

The companies said in the press release that they expect to produce globally up to 50 million vaccine doses in 2020 and up to 1.3 billion doses in 2021.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.