Russia's Sputnik V vaccine against Covid-19 is 83% effective against the Delta variant of Covid-19, lower than previously thought, Health Minister Mikhail Murashko said on Wednesday.

In June, the vaccine's developers said that Sputnik V was around 90% effective against the Delta variant. The claim had come at a time in June and July when authorities had blamed a surge in the coronavirus cases on the more contagious Delta variant and the population's reluctance to get vaccinated despite shots being widely available.

But the latest results show that effectiveness is around 83%, TASS news agency cited Murashko as saying.

Meanwhile, Alexander Gintsburg, director of the Gamaleya Institute which developed the vaccine, has reassured that Sputnik V was safe and effective against all strains of the coronavirus.