(Recasts following official statement, adds quotes)
MOSCOW, April 19 (Reuters) - Russian scientists have found the Sputnik V vaccine 97.6% effective against COVID-19 in a "real-world" assessment based on data from 3.8 million people, Moscow's Gamaleya Institute and the Russian Direct Investment Fund said on Monday.
The new effectiveness rate is higher than the 91.6% rate outlined in results from a large-scale trial of Sputnik V that was published in The Lancet medical journal earlier this year, and compares favourably with data on the effectiveness of other COVID-19 vaccines.
The new data was based on 3.8 million Russians who received both a first shot and a booster shot as part of the national roll-out of Sputnik V.
"This data confirms that Sputnik V demonstrates one of the best protection rates against coronavirus among all vaccines," said Kirill Dmitriev, head of the RDIF sovereign wealth fund which is backing the vaccine.
The incidence of infection was calculated from the 35th day from the first injection, the statement said, showing an incidence rate of 0.027%.
The incidence of infection among unvaccinated adults during a considerable period following the launch of mass vaccination in Russia was 1.1%, it said, without specifying the date range used.
The new data will be published in a peer-reviewed medical journal next month, the statement added.
The data was collated from a database kept by the health ministry that registers vaccinated people, as well as a separate database of people who were infected with COVID-19 in the country, the statement said. (Reporting by Polina Ivanova; Editing by Catherine Evans and Timothy Heritage)