COVID vaccine | Sputnik V shows 91.4% efficacy in second interim analysis on day 28 after first dose

Gamaleya Center and Russia’s sovereign wealth fund RDIF on November 24 announced that their coronavirus vaccine Sputnik V has demonstrated 91.4 percent efficacy in preventing COVID-19 infection in the second interim analysis on day 28 after the first dose, and over 95 percent following 21 days after the second dose in phase-3 trials.

In the first interim analysis, which was done after 20 people contracting COVID-19, the vaccine had shown 92 percent efficacy.

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.

According to the protocol of phase-III clinical trials of the Sputnik V vaccine, its interim efficacy is calculated at three statistically significant representative checkpoints - 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.

Currently, as many as 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.

Pfizer-BioNTech and Moderna vaccines have shown better efficacy at 95 percent, while AstraZeneca-University of Oxford vaccine had shown 70.4 percent efficacy.

“Gamaleya Center has developed one of the most efficient vaccines against coronavirus in the world with an efficacy rate of more than 90 percent and a price that is two times lower than that of other vaccines with similar efficacy rate," said Kirill Dmitriev, CEO, Russian Direct Investment Fund.

The announced price of Pfizer vaccines is around $19.50 and Moderna is expected to be priced at $25-$37 per dose, which excludes the cost of storage and administration.

"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,” Dmitriev added.

Russian authorities said 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, Gamaleya Center will provide access to the full clinical trial report.

"There were no unexpected adverse events during the trials. Monitoring of the participants is ongoing," a statement from makers of Sputnik V 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 percent," said Gamaleya Center Director Alexander Gintsburg.

"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 immunisation when the body’s strongest and most stable response is achieved," Gintsburg said.

"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,” Gintsburg added.

RDIF said there are requests for more than 1.2 billion doses of Sputnik V vaccine from more than 50 countries. The vaccine supplies for the global market will be produced by RDIF’s international partners in India, Brazil, China, South Korea and other countries.