The drug maker Pfizer announced on Monday that an early analysis of its coronavirus vaccine trial suggested the vaccine was robustly effective in preventing Covid-19, a promising development as the world has waited anxiously for any positive news about a pandemic that has killed more than 1.2 million people.
Pfizer, which developed the vaccine with the German drugmaker BioNTech, released only sparse details from its clinical trial, based on the first formal review of the data by an outside panel of experts.
The company said that the analysis found that the vaccine was more than 90 percent effective in preventing the disease among trial volunteers who had no evidence of prior coronavirus infection. If the results hold up, that level of protection would put it on par with highly effective childhood vaccines for diseases such as measles. No serious safety concerns have been observed, the company said.
Pfizer plans to ask the Food and Drug Administration for emergency authorization of the two-dose vaccine later this month, after it has collected the recommended two months of safety data. By the end of the year it will have manufactured enough doses to immunise 15 to 20 million people, company executives have said.
“This is a historical moment,” Kathrin Jansen, a senior vice president and the head of vaccine research and development at Pfizer, said in an interview. “This was a devastating situation, a pandemic, and we have embarked on a path and a goal that nobody ever has achieved — to come up with a vaccine within a year.”
Independent scientists have cautioned against hyping early results before long-term safety and efficacy data has been collected. And no one knows how long the vaccine’s protection might last. Still, the development makes Pfizer the first company to announce positive results from a late-stage vaccine trial, vaulting it to the front of a frenzied global race that began in January and has unfolded at record-breaking speed.
Eleven vaccines are in late-stage trials, including four in the United States. Pfizer’s progress could bode well for Moderna’s vaccine, which uses similar technology. Moderna has said it could have early results later this month.
The news comes just days after Joseph R Biden Jr clinched a victory over President Trump in the presidential election. Mr. Trump had repeatedly hinted a vaccine would be ready before Election Day, November 3.
This fall, Pfizer’s chief executive, Dr. Albert Bourla, frequently claimed that the company could have a “readout” by October, something that did not come to pass.
Operation Warp Speed, the federal effort to rush a vaccine to market, has promised Pfizer $1.95 billion to deliver 100 million doses to the federal government, which will be given to Americans free of charge. But Dr. Jansen sought to distance the company from Operation Warp Speed and presidential politics, noting that the company — unlike the other vaccine front-runners — did not take any federal money to help pay for research and development. “We were never part of the Warp Speed,” she said. “We have never taken any money from the US government, or from anyone.”