The efficacy of the Sputnik V vaccine is 91.4%, based on the second interim analysis of data obtained 28 days after administering the first dose (seven days after the second dose), according to the Gamaleya Center and the Russian Direct Investment Fund (RDIF).
The calculation was based on the analysis of data on volunteers (18,794) who received both the first and second doses of the Sputnik V vaccine or placebo at the second control point (39 confirmed cases as of November 23, 2020) in accordance with the clinical trial protocol.
Preliminary data from volunteers obtained 42 days after the first dose (corresponds with 21 days after the second dose) indicates an efficacy of the vaccine above 95%.
The interim research data will be published by the Gamaleya Center team in a leading international peer-reviewed medical journal. Following the completion of Phase III clinical trials of the Sputnik V vaccine, Gamaleya Center will provide access to the full clinical trial report.
Currently, 40,000 volunteers are taking part in the Phase III double-blind, randomised, placebo-controlled clinical post-registration study of the Sputnik V vaccine in Russia, of whom more than 22,000 volunteers were vaccinated with the first dose and more than 19,000 volunteers with the first and second doses.
There were no unexpected adverse events during the trials. Monitoring of the participants is ongoing.
The Sputnik V vaccine is based on a human adenoviral vector platform. The uniqueness of the Russian vaccine lies in the use of two different vectors based on the human adenovirus, which allows for a stronger and longer-term immune response as compared to vaccines using one and same vector for two doses. So, preliminary data on volunteers on the 42nd day after the first dose (equivalent to 21 days after the second dose), when they have already formed a stable immune response, indicates the efficacy rate of the vaccine is above 95%.
Mikhail Murashko, Minister of Health of the Russian Federation, said: “The data demonstrating high efficacy of the Sputnik V vaccine give us hope that we will soon obtain the most important tool in the fight against the pandemic of the novel coronavirus infection”.
Alexander Gintsburg, Gamaleya Center Director, said: “It is very important that the second interim efficacy analysis of Sputnik V has confirmed our findings from the first stage and shown its efficacy at 91-92%. Let me stress that the second analysis was conducted a week after volunteers got the second dose, meaning that their bodies have partially reacted to both doses. We expect the efficacy rate to be even higher based on the data three weeks after the second immunization when the body’s strongest and most stable response is achieved. We plan to conduct the third interim data analysis after 78 confirmed coronavirus cases among volunteers and we have every reason to believe that the results will exceed our initial expectations. The drug’s final efficacy assessment will be made available after Phase III clinical trials are concluded.”
Image credit: Sam Moqadam