Biontech SE and Pfizer Inc. scored a major win in their phase III trial with COVID-19 vaccine BNT-162b2, gaining 90% efficacy in preventing infection at the first interim analysis by an external, independent data monitoring committee (DMC). The study enrolled 43,538 subjects, 42% of diverse backgrounds globally, and no safety concerns turned up.

Shares of Mainz, Germany-based Biontech (NASDAQ:BNTX) were trading premarket at $115.50, up $23.50, or 25%. Pfizer, of New York (NYSE:PFE), was selling for $41.49, up $5.09, or about 14%.

The analysis evaluated 94 confirmed cases of COVID-19. After talks with the FDA, the companies decided to drop the 32-case interim analysis and conduct the first interim analysis at a minimum of 62. Between vaccinated individuals and those who received the placebo, the case split indicates a vaccine efficacy rate above 90% at seven days after the second dose, so protection is achieved 28 days after the start of the two-dose schedule. The DMC said the study should continue. Meanwhile, Biontech and Pfizer said they will discuss the findings thus far with regulatory authorities worldwide.

Begun this summer, the study had given the second dose to 38.955 participants as of Nov. 8. Among those in the U.S., 30% show racially and ethnically diverse backgrounds. The trial continues to enroll, and is expected to keep going through the final analysis, when a total of 164 confirmed COVID-19 cases have accrued. Also to be explored is the possibility that BNT-162b2, which encodes an optimized SARS-CoV-2 full-length spike glycoprotein, could protect people who’ve had prior exposure to the virus, as well as its prospects against severe COVID-19 disease.

Along with the primary efficacy endpoints in confirmed COVID-19 cases that accrue from seven days after the second dose, the final analysis will include, with the FDA’s blessing, new secondary efficacy endpoints based on cases accruing 14 days after the second dose. Adding the secondary endpoints in the updated protocol should help align data across all COVID-19 vaccine studies, which would allow for informative comparisons. Participants will be monitored for two years after their dosing is completed.

The companies said a median of two months of safety data following the second (final) dose, which is what the FDA needs for potential emergency use authorization (EUA), will be available by the third week of this month. Biontech and Pfizer are putting together safety data related to manufacturing, too. They expect to crank out globally up to 50 million vaccine doses in 2020 and up to 1.3 billion doses in 2021. Data from the full phase III will be submitted to a scientific journal.

SVB Leerink analyst Geoffrey Porges said in a report that the disclosure “looks very promising” and “should beat expectations of most investors and the market,” as well as provide “a welcome boost to sentiment going into an epidemiologically challenging winter season.” Mizuho’s Vamil Divan cheered, too, predicting the EUA by December, and pegging sales at more than $8.5 billion in the first year.