LONDON – Efficacy data for Russia’s Sputnik V COVID-19 vaccine held steady at 91.4% in the second interim analysis, conducted after 39 confirmed cases of COVID-19 infection in 18,794 volunteers, seven days after they received the second dose.

Among the 14,095 people who received the vaccine, there were eight cases, while 31 of 4,699 volunteers who received placebo caught the virus.

“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%,” said Alexander Gintsburg, director of the Gameleya National Center of Epidemiology and Microbiology, where the vaccine was developed.

Efficacy will increase Gintsburg said. “Let me stress the second analysis was conducted a week after volunteers got the second dose, meaning 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.”

That appears to be borne out by preliminary data based on responses 21 days after the second dose, which indicate Sputnik V is more than 95% effective.

There is to be a third and final analysis once there are 78 confirmed COVID-19 cases among 40,000 volunteers taking part in the trial. To date, more than 22,000 have received the first dose, and more than 19,000 have received both doses, administered 21 days apart.

Kirill Dmitriev, CEO of the Russian Direct Investment Fund (RDIF), the sovereign wealth fund that is supporting development of the vaccine, signing up international contract manufacturers and building a market for Sputnik V, gave the first indication of pricing, saying the cost in international markets will be less than $20 for the two doses that are required.

That is at least two times cheaper than Pfizer Inc./Biontech SE and Moderna Inc.’s mRNA vaccines, Dmitriev noted. “The Gamaleya Center has developed one of the most efficient vaccines against coronavirus in the world, with an efficacy rate of more than 90% and a price that is two times lower than that of other vaccines with similar efficacy,” he said.

Russian citizens will be vaccinated for free. Currently, the country is recording around 25,000 new cases per day, up from 5,000 infections per day at the end of September.

Agreements sealed with foreign manufacturers will see 1 billion doses of Sputnik V produced outside Russia in 2021. RDIF is assessing other potential partners to increase production and said it has received requests for more than 1.2 billion doses from more than 50 countries. The first international deliveries will be made in January 2021.

One of the international partners is GL Rapha, a South Korean biotech, which has agreed to produce more than 150 million doses per year, with production due to start in December 2020.

Sputnik V will not only be cheaper than mRNA vaccines, it also will be easier to transport and store. RDIF and partners have launched production of a lyophilized formulation, which can be stored at fridge temperatures of 2 to 8 degrees Celsius, enabling it to be distributed and administered through existing infrastructure.

In parallel with the trial in Russia, there also are Sputnik phase III trials ongoing in Belarus, United Arab Emirates and Venezuela, while a phase II/III is taking place in India. A separate study is assessing safety and immunogenicity in the elderly. Sputnik V has been filed for regulatory approval in Brazil.

Sputnik V uses recombinant human adenovirus type 26 and recombinant human adenovirus type 5, both of which are engineered to express the spike protein. Use of two different adenoviruses is intended to ensure that if immunity develops to the first, the second booster shot remains effective.

RDIF points to the long history of safety and efficacy of human adenoviral vectored products, noting they have been tested in more than 250 clinical studies. Since 2015, more than 3,000 people have been vaccinated with Ebola and Middle East respiratory syndrome vaccines developed at the Gamaleya Center.

As of Nov. 24, no unexpected adverse events have been seen in the phase III, which is described by the Gamaleya Center as being a post-registration study, because the vaccine was given emergency approval on Aug. 11, based on two – as then – unpublished phase II trials.

That stirred controversy outside Russia, but Dmitriev previously has pointed out that Russia’s rules prohibit publication of trial results before regulators consider the file, as it is felt that could influence their judgement.

Dmitriev also has said international skepticism about the conduct of the trial and the quality of the science is a result of “major bias against Russia.”