Russian Federation approved the vaccine in August, before the large-scale trial had begun, saying it was the first country to do so for a Covid-19 shot.
The team also analyzed the efficacy of the vaccine against severe and moderate Covid-19 disease and 21 days after the first dose no severe or moderate cases were reported in the vaccinated group, while 20 were reported in the placebo group.
As well as proving effective, it was also safe with no serious reactions linked to the vaccine during the trial. In the period after administering the the first shot, 16 cases of Covid-19 were found in the 14,964 people (0.1%) part of the vaccine group, while 62 infections were reported in the 4,902 individuals (1.3%) in the placebo group. Sixty two cases were found in the placebo group - equating to an efficacy of 91.6%.
No serious adverse events were deemed to be associated with vaccination, and most reported adverse events were mild, including flu-like symptoms, pain at the injection site and weakness or low energy.
Researchers say, based on their trial that involved about 20,000 people in Russian Federation last fall, the vaccine is about 91% effective and appears to prevent people from becoming severely ill with COVID-19. So far around 20,000 participants, mostly white, have been involved in the trials.
"So we should be more careful about being overly critical about other countries' vaccine designs".
But the Russian vaccine has been treated with suspicion due to a lack of publicly available scientific data.
Sputnik V - a two-dose vaccine using adapted strains of the adenovirus, a virus that causes the common cold - is set to be produced as "Sputnik Light", a less effective single-dose version. Further research is needed to understand the efficacy of the vaccine on asymptomatic Covid-19, and transmission, according to the researchers.
The trial is now ongoing and aims to include a total of 40,000 participants.
Dolzhikova works at Russia's Gamaleya National Research Centre for Epidemiology and Microbiology, which developed the vaccine.
Health workers getting against COVID-19 with the Sputnik V vaccine in Buenos Aires on 2 February 2021.
In addition to its contract with Gamaleya, Argentina has agreements with the pharmaceutical company AstraZeneca and the University of Oxford regarding their vaccine, and another deal with the Covax mechanism of the World Health Organisation (WHO), through which as many as nine million doses could arrive. Developers said this minimises the risk of the immune system developing resistance to the initial vector, which may help create a more powerful response.
"This is a great day in the fight against the COVID-19 pandemic", said Kirill Dmitriev, CEO of the Russian Direct Investment Fund that bankrolled the development of the shot. Also, the durability of the protection offered by the vaccine remains to be seen as patients were followed for up to 48 days after their first dose.
The piece of DNA in the Russian vaccine includes instructions for making the SARS-CoV-2 spike proteins - the crown-like studs the coronavirus uses to enter cells.
Sputnik V, named after the former Soviet space satellites, has been shrouded in controversy since Vladimir Putin green-lit its approval for mass-use in Russian Federation last August before any human trials had been conducted.
Outside Russia, Sputnik V has received authorization in over a dozen countries, according to the fund - including the former Soviet republics of Belarus, Armenia and Turkmenistan; Latin American nations including Argentina, Bolivia and Venezuela; African nations such as Algeria as well as Serbia, Iran, Palestine and UAE.
"So we should be more careful about being overly critical about other countries' vaccine designs/ programs", he said.