The results are based on the first interim efficacy analysis from the phase III study. After the case count reached 94, a data analysis committee performed its first analysis on all cases between vaccinated individuals and those who received the placebo. The results indicate a vaccine efficacy rate above 90% at seven days after the second dose of the two-dose regimen (28 days after the initial dose).

The committee did not report any serious safety concerns and recommended that the study continue to collect additional safety and efficacy data.

The phase III trial began on July 27 and has enrolled 43,538 participants to date, with 38,955 having received the second dose as of November 8. The trial is continuing to enroll participants and is expected to continue through the final analysis when a total of 164 confirmed COVID-19 cases have accrued. The study will also evaluate the vaccine candidate's ability to provide protection against COVID-19 in those who have had prior exposure to SARS-CoV-2, as well as vaccine prevention against severe COVID-19 disease.

The companies are continuing to collect safety data for a projected two months after administration of a second dose, the amount of time specified by the U.S. Food and Drug Administration (FDA) emergency use authorization (EUA) guidance, which they anticipate will be available during the third week of November.

Pfizer and BioNTech are working to prepare safety and manufacturing data to submit to the FDA to demonstrate the safety and quality of the vaccine product produced. The companies project that they can produce up to 50 million doses of the vaccine in 2020 and up to 1.3 billion doses in 2021.