Second analysis suggests Gamaleya's COVID-19 vaccine Sputnik V 91.4% effective

A new update from a Phase III study of the Gamaleya Institute's COVID-19 vaccine Sputnik V suggests that it has an efficacy rate of 91.4% as measured seven days after administration of the second dose, the Russian Direct Investment Fund (RDIF) announced Tuesday. The second interim analysis of the trial was performed after 39 confirmed cases of coronavirus, with 31 cases in the placebo group versus eight cases in those who received Sputnik V.

Earlier this month, results from the first interim analysis of the study showed that Sputnik V had an efficacy rate of 92% after the second dose, based on 20 confirmed cases of coronavirus. RDIF noted that the next interim analysis will be conducted when 78 confirmed coronavirus cases have been recorded.

Efficacy increases 21 days after second dose

According to RDIF, the latest evaluation included 18,794 participants in the study, comprising 14,095 in the vaccine group and 4699 in the placebo arm, and was conducted 28 days after receiving the first dose. Preliminary data also showed that 42 days after the first dose of Sputnik V, corresponding to 21 days after the second dose, the efficacy rate of the vaccine is above 95%.

Alexander Gintsburg, Gamaleya centre director, remarked "the second analysis was conducted a week after volunteers got the second dose, meaning that their bodies have partially reacted to both doses." Gintsburg said "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."

RDIF added that as of November 24, over 22,000 subjects have been vaccinated with the first dose of Sputnik V, while more than 19,000 have received both the first and the second immunisations. The investment fund said that as of this date, "no unexpected adverse events were identified," with some vaccinated participants experiencing "short-term minor adverse events," including pain at the injection site and influenza-like symptoms, such as fever, weakness, fatigue and headache.

Cost set at under $10 per dose

Separately on Tuesday, RDIF disclosed that the cost of Sputnik V for international markets will be less than $10 per dose starting from February 2021, with two doses required to vaccinate one person. The investment fund added that the vaccine will be free for Russian citizens.

RDIF indicated that it has launched production of the lyophilised form of the vaccine, which can be stored at temperatures of between 2 and 8 degrees Celsius, and plans to produce enough doses for more than 500 million people next year. The investment fund added that "the first international deliveries…will be made to customers in January 2021 based on the existing partnerships with foreign manufacturers."

The data for Sputnik V come the day after the first Phase III data for another adenovirus-based vaccine, AstraZeneca's AZD1222, were released. A combined interim analysis of late-stage studies showed that AZD1222 had an average efficacy of 70%, increasing to 90% for a regimen that included initial immunisation with a half dose. For related analysis, see ViewPoints: Nuances necessary when comparing the newest COVID-19 vaccine, and ViewPoints: Leading expert weighs in on AstraZeneca’s serendipitous COVID-19 vaccine finding.

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