Pfizer Inc. and BioNTech SE have announced an interim analysis from a phase III trial of their COVID-19 vaccine candidate. Based on the first interim efficacy analysis, the mRNA-based vaccine candidate, BNT162b2, has demonstrated evidence of efficacy against COVID-19 in participants without prior evidence of SARS-CoV-2 infection.

The randomized placebo-controlled phase III clinical trial began on July 27, 2020 and has enrolled 43,538 participants to date. The first interim efficacy analysis was conducted on November 8, 2020 by an external, independent Data Monitoring Committee. BNT162b2 is administered over 2 doses 21 days apart; the interim analysis indicates a vaccine efficacy rate above 90% at 7 days after the second dose. At the data cutoff for this interim analysis, 38,955 participants had received a second dose. 

The trial is continuing to enroll, and will continue through the final analysis when a total of 164 confirmed COVID-19 cases have accrued (second safety milestone). Submission for Emergency Use Authorization (EUA) to the Food and Drug Administration (FDA) is planned for soon after the required safety milestone is achieved, which is currently expected to occur in the third week of November. The study will also evaluate the potential for the vaccine candidate 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.

Pfizer Inc. Pfizer and BioNTech Announce Vaccine Candidate Against COVID-19 Achieved Success in First Interim Analysis from Phase 3 Study [news release]. November 9, 2020. Available at: click here. Accessed November 9, 2020.