Early data for Russia’s coronavirus vaccine suggests it is 92% effective, the country’s sovereign wealth fund has said.
The announcement on the Sputnik V vaccine comes days after pharmaceutical giant Pfizer and biotech firm BioNTech released interim results suggesting their vaccine is more than 90% effective at preventing Covid-19.
The phase three trials evaluated efficacy among more than 16,000 volunteers who received the vaccine or placebo 21 days after the first injection.
Statistical analysis of 20 confirmed cases of coronavirus, the cases split between vaccinated individuals and those who received the placebo, indicates the vaccine had an efficacy rate of 92% after the second dose.
The Russian Direct Investment Fund (RDIF), which has been backing the vaccine, said there were no unexpected adverse events during the trials, and monitoring of the participants is continuing.
The results have not been peer-reviewed.
The phase three study of the vaccine, developed by the Gamaleya Institute, is taking place in 29 clinics across Moscow and will involve 40,000 volunteers in total, with a quarter receiving a placebo shot.
Denis Logunov, deputy director of the Gamaleya Centre, said: “Positive interim results of phase three give reasons to expect a successful outcome of Sputnik V clinical trials.
“We will continue to process and analyse all the data and look to the future with optimism, expecting that results of our work will help end the pandemic sooner.”
The news comes as reports suggest three doctors in Russia caught coronavirus after being injected with the vaccine.
Chief epidemiologist of the Altai Territory, Irina Pereladova, told local news website amic.ru there is no guarantee from a single vaccination that a person will not get sick after it, because they may already have the virus but be in the incubation period.
She added the medics were likely infected in the 24 hours between having negative tests and the first jab.
The website reports all the doctors tested negative for coronavirus a day before the first vaccination, but pre-vaccination tests for coronavirus are not mandatory.
Eleanor Riley, professor of immunology and infectious disease at the University of Edinburgh, said: “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.
“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.
“Anything less than this risks a public loss of trust in all vaccines, which would be a disaster.”
Ian Jones, professor of virology, University of Reading, said: “The Sputnik data is yet more good news for Covid-19 vaccine development.
“Although based on fewer cases than the recent Pfizer data, the vaccine looks as efficient and, like the Pfizer data, confirms and extends the earlier phase two results.
“We still need to know about the longevity of the response and the efficiency in different age groups, but the result bodes well for the other trials currently in progress and for having enough vaccine in geographically diverse regions to enable a comprehensive vaccination programme on a global scale.”