Russia's Sputnik V vaccine has shown 92 per cent efficacy in preventing COVID-19, according to interim trial results announced by the country's health ministry on Wednesday.
The announcement follows results unveiled earlier this week by vaccine developers Pfizer and BioNTech, who said their vaccine was more than 90 per cent effective at preventing COVID-19.
The calculation is based on the 20 confirmed COVID-19 cases split between vaccinated individuals and those who received the placebo, said Russian Direct Investment Fund.
The efficacy of the vaccine, developed by the Gamalaya Centre, was demonstrated on the basis of a first interim analysis obtained 21 days after the first injection.
There were no unexpected adverse events during the trials. Monitoring of the participants is ongoing, the ministry said.
The interim research data of Sputnik V has not been published or peer-reviewed yet.
Currently, 40,000 volunteers are taking part in Phase III of Sputnik V clinical trials, out of which over 20,000 have been vaccinated with the first dose of the vaccine and more than 16,000 with both the first and second doses of the vaccine.
"The publication of the interim results of the post-registration clinical trials that convincingly demonstrate Sputnik V vaccine's efficacy gives way to mass vaccination in Russia against COVID-19 in the coming weeks," Alexander Gintsburg, director of the Gamaleya Center said in a statement.
"Thanks to the production scale up at new manufacturing sites, Sputnik V vaccine will soon be available for a wider population. This will break the current trend and lead to an eventual decrease in COVID-19 infection rates, first in Russia, then globally," Gintsburg said.
Eleanor Riley, Professor of Immunology and Infectious Disease, University of Edinburgh in the UK said while the results are encouraging, "I worry that these data have been rushed out on the back of the Pfizer/BioNtech announcement earlier in the week."
"The Sputnik data are based on only 20 cases of COVID-19 in the trial participants, compared to more than 90 cases in the earlier trial. This is not a competition," he said.
"We need all trials to be a carried out to the highest possible standards and it is particularly important that the pre-set criteria for unblinding the trial data are adhered to avoid cherry picking the data," Riley said, adding anything less than this risks a public loss of trust in all vaccines, which would be a disaster.
Currently, Sputnik V Phase III clinical trials are approved and are undergoing in Belarus, UAE, Venezuela and other countries, as well as Phase II-III in India.
The Sputnik V vaccine is based on a human adenoviral vector platform that had proven safe and effective with no long-term side effects in more than 250 clinical trials globally conducted during the past two decades, the ministry said.
The Russian vaccine uses two different human adenoviral vectors that enable to provide strong and long-term immune response after the second injection.