Russia’s Sputnik V vaccine is 91.6 percent effective against symptomatic Covid-19, according to results published Tuesday.

Sputnik V — named after the Soviet-era satellite — was approved in Russia months before results from its final-stage clinical trials were published, leading to scepticism from experts.

The preliminary findings in The Lancet on Tuesday are based on data gathered from 19,866 participants, out of which around three-quarters (14,964) received two doses of the vaccine and a quarter (4,902) were given a placebo.

Sixteen cases of symptomatic Covid-19 were confirmed in the vaccine group 21 days after participants received the first vaccine dose. Sixty two cases were found in the placebo group — equating to an efficacy of 91.6%.

The trial included 2,144 people over the age of 60 and a sub-analysis conducted on this group revealed the vaccine was well tolerated and had a similar efficacy of 91.8%.

The results suggest Sputnik V is among the top-performing vaccines, along with the Pfizer/BioNTech and Moderna jabs that also reported more than 90 percent efficacy.

Sputnik V has the advantage of being able to be kept at normal refrigerator temperatures instead of the conditions of far below freezing required for some other vaccines.

The Lancet report said that during the trial “no serious adverse events were deemed to be associated with vaccination”.