US pharmaceutical giant Pfizer and German biotech firm BioNTech said their coronavirus vaccine was more than 90 per cent effective in preventing COVID-19 among those without evidence of prior infection, in a major breakthrough that could make the shot available for use by the end of the year if drug authorities give it the green light. It comes as drugmakers and research centers around the world scramble to deliver a safe and effective vaccine in an attempt to bring an end to the coronavirus pandemic that has claimed over 1.25 million lives worldwide.
The finding was the result of the first independent analysis of any Covid-19 vaccine in phase 3 trials — the final stage before commercial licensing. The study found that 94 participants who received the two-dose vaccine were protected against the disease 28 days after their first inoculation.
“Today is a great day for science and humanity. The first set of results from our Phase 3 COVID-19 vaccine trial provides the initial evidence of our vaccine’s ability to prevent COVID-19,” said Dr. Albert Bourla, Pfizer Chairman and CEO.
“The first interim analysis of our global Phase 3 study provides evidence that a vaccine may effectively prevent COVID-19. This is a victory for innovation, science and a global collaborative effort,” said Prof. Ugur Sahin, BioNTech co-founder and CEO.
The Phase 3 clinical trial of BNT162b2 began on July 27 and has enrolled 43,538 participants to date, 38,955 of whom have received a second dose of the vaccine candidate as of November 8, 2020. Approximately 42% of global participants and 30% of U.S. participants have racially and ethnically diverse backgrounds. The trial is continuing to enroll and is expected to continue through the final analysis when a total of 164 confirmed COVID-19 cases have accrued.
- Vaccine candidate was found to be more than 90% effective in preventing COVID-19 in participants without evidence of prior SARS-CoV-2 infection in the first interim efficacy analysis.
- Analysis evaluated 94 confirmed cases of COVID-19 in trial participants.
- Study enrolled 43,538 participants, with 42% having diverse backgrounds, and no serious safety concerns have been observed; Safety and additional efficacy data continue to be collected.
- Submission for Emergency Use Authorization (EUA) to the U.S. Food and Drug Administration (FDA) planned for soon after the required safety milestone is achieved, which is currently expected to occur in the third week of November.
- Clinical trial to continue through to final analysis at 164 confirmed cases in order to collect further data and characterize the vaccine candidate’s performance against other study endpoints.
The shots made by Pfizer and its German partner BioNTech are among 10 possible vaccine candidates in late-stage testing around the world — four of them so far in huge studies in the U.S. Another U.S. company, Moderna Inc., also has said it hopes to be able to file an application with the Food and Drug Administration later this month.
Volunteers in the final-stage studies, and the researchers, don’t know who received the real vaccine or a dummy shot. But a week after their second required dose, Pfizer’s study began counting the number who developed COVID-19 symptoms and were confirmed to have the coronavirus.
Pfizer doesn’t plan to stop its study until it records 164 infections among all the volunteers, a number that the FDA has agreed is enough to tell how well the vaccine is working. The agency has made clear that any vaccine must be at least 50% effective.
No participant so far has become severely ill, Gruber said. Nor could he provide a breakdown of how many of the infections had occurred in older people, who are at highest risk from COVID-19.
Participants were tested only if they developed symptoms, leaving unanswered whether vaccinated people could get infected but show no symptoms and unknowingly spread the virus.