Sputnik V vaccine efficacy is over 95% 42 days after the first dose
MOSCOW – The National Research Center for Epidemiology and Microbiology named after N.F. Gamaleya of the Ministry of Health of the Russian Federation (Gamaleya Center) and Russia’s sovereign wealth fund Russian Direct Investment Fund (RDIF), announced positive results obtained during the second interim data analysis of the largest double-blind, randomized, placebo-controlled Phase III clinical trials in Russia’s history involving 40,000 volunteers.
Interim trial results have once again confirmed the high efficacy of the Sputnik V vaccine, the world’s first registered vaccine against coronavirus based on a well-studied platform of human adenoviral vectors. Evaluation of efficacy was carried out among volunteers 28 days after receiving the first dose (7 days after the second dose) of the vaccine or placebo upon reaching the second control point of the trial in compliance with the clinical trial protocol. The analysis demonstrated a 91.4% efficacy rate for the Sputnik V vaccine.
According to the protocol of Phase III clinical trials of the Sputnik V vaccine, its interim efficacy is calculated at three statistically significant representative control points – upon reaching 20, 39 and 78 cases of novel coronavirus infection among volunteers both in the placebo group and in the group that received the vaccine. The second interim analysis of the Sputnik V vaccine efficacy was carried out on the basis of 39 confirmed cases identified in the placebo group (31 cases) and in the vaccine group (8 cases). The ratio of the placebo group to the vaccinated group is 1 to 3.
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 the 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%.
The next interim data analysis will be conducted upon reaching the third control point of 78 confirmed coronavirus cases among the study participants. Final data analysis will be available by the end of Phase III clinical trials.
The interim research data will be published by the Gamaleya Center team in one of the leading international peer-reviewed medical journals. Following the completion of Phase III clinical trials of the Sputnik V vaccine, the Gamaleya Center will provide access to the full clinical trial report.
As of Nov. 24 more than 22,000 volunteers were vaccinated with the first dose and more than 19,000 volunteers with the first and the second dose of the vaccine at 29 medical centers in Russia as part of the ongoing clinical trials. Currently Phase III clinical trials are approved and are ongoing in Belarus, the UAE, Venezuela and other countries, as well as Phase II-III in India.
As of Nov. 24, no unexpected adverse events were identified as part of the research. Some of those vaccinated had short-term minor adverse events such as pain at the injection point and flu-like symptoms including fever, weakness, fatigue, and headache.
During the clinical trials, the safety of the vaccine is constantly being monitored; information is analyzed by the Independent Monitoring Committee comprising leading Russian scientists. Collection, quality control and data processing is conducted in line with ICH GCP standards and involves the active participation of Moscow’s Health Department and Crocus Medical, the contract research organization (CRO).
Minister of Health of the Russian Federation Mikhail Murashko said: "The data demonstrating high efficacy of the Sputnik V vaccine gives us hope that we will soon obtain the most important tool in the fight against the pandemic of the novel coronavirus infection."
Gamaleya Center Director Alexander Gintsburg 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."
Gamaleya Center Deputy Director Denis Logunov commented: "Results from the second interim analysis of the Sputnik V vaccine are in line with our expectations and predictions. The vaccine’s high efficacy rate is an important indication that a stable immune response to the coronavirus infection is formed among the study’s participants.
"We expect that the next interim results will demonstrate Sputnik V’s positive traits, moving us closer to the study’s completion and the beginning of a mass vaccination of our fellow citizens."
Russian Direct Investment Fund CEO Kirill Dmitriev said: "The Gamaleya Center has developed one of the most efficient vaccines against coronavirus in the world with an efficacy rate of more than 90%. The uniqueness of the Russian vaccine lies in the use of two different human adenoviral vectors which allows for a stronger and longer-term immune response as compared to the vaccines using one and the same vector for two doses." – SG