Pfizer and BioNTech have announced that the first interim efficacy analysis data from the trial of BNT162b2 revealed that the vaccine was more than 90% effective in preventing Covid-19 in participants without evidence of prior SARS-CoV-2 infection.
BNT162b2 is an mRNA-based vaccine candidate co-developed by Pfizer and BioNTech.
To date, the Phase III trial which began in July has enrolled 43,538 subjects and 38,955 of them were given a second dose.
It is enrolling patients and will continue through the final analysis when a total of 164 confirmed Covid-19 cases have accrued.
Furthermore, the trial will evaluate whether BNT162b2 can provide protection against Covid-19 to those who were exposed to SARS-CoV-2 and as prevention against the disease.
Apart from the primary efficacy endpoints analysing confirmed Covid-19 cases accruing from seven days after the second dose, the final analysis will trial efficacy based on cases accruing 14 days.
The companies decided to conduct the first interim analysis at a minimum of 62 cases after holding discussions with the US Food and Drug Administration (FDA).
Upon conclusion of the talks, the evaluable case count stood at 94 and the first analysis was conducted by an external, independent Data Monitoring Committee (DMC) on 8 November on all cases.
At seven days after the second dose, the results showed that the individuals who received BNT162b2 had a vaccine efficacy rate above 90% as compared to placebo.
This implies that the vaccine could provide protection in 28 days after the initiation of the vaccination, which consists of a two-dose schedule.
Pfizer chairman and CEO Dr Albert Bourla said: “We are reaching this critical milestone in our vaccine development programme at a time when the world needs it most with infection rates setting new records, hospitals nearing over-capacity and economies struggling to reopen.”
Last month, the companies initiated combined Phase I and Phase II trials of the vaccine candidate in Japan.
In a separate development, Russia reported that its vaccine against Covid-19, Sputnik V, was also found to be more than 90% effective.
Reuters quoted Russian health ministry, research institute director Oksana Drapkina as saying in a statement: “Based on our observations, its effectiveness is also more than 90%. The appearance of another effective vaccine, this is good news for everyone.”
The data is collated from vaccinations of the public rather than from an ongoing trial.