When Russia announced this week that its much-hyped COVID-19 vaccine was up to 95 per cent effective, the news was met with a predictable cheer in Russia and uncertainty throughout much of Europe and North America."This is great news for Russia and great news for the world," gushed Kirill Dmitriev, head of the Russian Direct Investment Fund, which is pouring countless millions of Russian tax dollars into developing the vaccine it labelled early on as Sputnik V.Whether the V stands for "five" or simply the letter "V" has never been fully explained, but either way the association is obvious: the original Sputnik satellite won Russia the space race more than 60 years ago, and this new Sputnik will make Russia first in this new race to defeat the pandemic.With its hyperbolic announcements and an ambitious — some would say unattainable — timetable, the Putin government has attempted to demonstrate the development of Sputnik V has made Russia a vaccine superpower.WATCH | Russia claims its COVID-19 vaccine is highly effective:Already, among the reputed "firsts" Russia is claiming: the first COVID vaccine in the world to be registered; the first vaccine anywhere to be announced as part of a national vaccination campaign; and trial results that rank it first in terms of effectiveness.Not to be outdone, when Pfizer and BioNTech became the first Western vaccine maker to announce promising results, with 90 per cent efficacy, days later Sputnik V's makers said their vaccine was even better — by two percentage points. Some Western experts have felt opaqueness about the Russian approval process, combined with a rush to get it registered even before trials started, damaged the vaccine's credibility from the outset.Russia licensed it based on early trials involving only 76 people, whereas usually most approvals come after Phase 3 studies involving tens of thousands of subjects. Even after those early results were published in the reputable medical journal The Lancet, a group of 37 scientists from 12 countries wrote the publication questioning the data.Russian officials and state media pundits have decried the skepticism as evidence of an inherent "Western bias" against anything Russian and have accused U.S. and U.K. media of staging a smear campaign to steal away potential international customers. Positive resultsFast forward to this week and news from Sputnik's developer, the Gamaleya Research Institute of Epidemiology and Microbiology, of very positive results from a much larger data sample. Russia's vaccine has 91.4 per cent efficacy from an analysis of more than 18,000 people, said a release on the Sputnik V website. The vaccine's efficacy rose to 95 per cent after 42 days. Plus, at roughly $20 US per person, Gamalyea says the Russian vaccine is one of the cheapest on the market, making it an attractive option for poorer countries with large populations.Like the vaccine developed by Oxford University and its partner AstraZeneca, the Russian vaccine uses human adenovirus vectors, or common cold genes, to trigger an immune response in the body. An initial shot is followed by a booster three weeks later.The news about the results prompted a change in tone from many Western vaccine experts. "The data [is] compatible with the vaccine being reasonably effective," said Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine."These results are consistent with what we see with other vaccines, because the really big message for global health scientists is that this disease [COVID-19] is able to be addressed by vaccines."Ian Jones, a professor of virology at the University of Reading, concurs."I see no reason to doubt it [the results]," Jones told CBC News in an interview. "I agree that their initial results caused consternation, but I don't think it's because they weren't valid. They were released a bit soon."I think it's going to be a useful vaccine."Their positive assessments are based on the knowledge that the adenovirus delivery method behind the Gamaleya-made vaccine has proven successful over and over again.What was unclear was whether the COVID-19 virus would be resistant, but Evans says the other drug companies' positive results strongly suggest the Russian vaccine will likely perform well, too."We now have four vaccines that have some efficacy [on COVID-19], which is way beyond what we have ever had for an HIV or a malaria vaccine," said Evans.Question of trustUltimately, he says whether a country chooses to buy the Russian-made vaccine comes down to a question of whether they have confidence in the science behind it and trust the regulators who approved it.The Russian vaccine gets treated more skeptically, said Evans, because the processes in the United States and Europe are far more open and transparent than they are in Russia."We do not know how carefully their trials are monitored and how carefully they are reported. We do not know that," he said. "But the countries that are buying it are buying it on trust that the Russians have produced something."Enrico Bucci, an Italian biologist who was part of the original group of scientists questioning the early Russian results, is among those who continue to believe that the Russian developers have not been sufficiently transparent about their data.For example, he says the claim of 91.4 per cent success is based on just 39 people in the 18,000-person sample contracting COVID-19."The sample is too low to claim any percentage of efficacy," Bucci told CBC News.Furthermore, he said, it's not clear where these 39 people came from, how old they were and whether the results from trials in one country were mixed with those from another location.The Oxford University/AstraZeneca vaccine — which reported a roughly 70 per cent success rate — has been subjected to similar criticisms about how data from its trials was presented, and its developers have now agreed to run new studies.So far, Hungary is the only member of the European Union to sign up for the Russian vaccine, although Russian media reports that 50 nations have either already signed deals for the vaccine or are in the process of negotiating them. On Friday, Russia announced a partnership with Indian pharmaceutical company Hetero to produce 100 million doses of the vaccine by the end of 2021.Canada has signed agreements with five vaccine manufacturers, but the list does not include Sputnik V.Gamalyea's initial estimates that Russia would be able to produce 200 million doses of Sputnik V by the end of next month turned out to be wildly optimistic. The health ministry now says it may be able produce two million doses, at best.Russians uncertainSince the summer, Russia's Health Ministry has been promising a national vaccination campaign was imminent, but it has been slow to roll out. President Vladimir Putin said one of his daughters was among the first to get the vaccine, although the Kremlin acknowledged this week that Putin himself has not. A spokesperson said it would be irresponsible for the head of state to take an "uncertified" vaccine, although the distinction the official was trying to make between a registered vaccine and a certified one was unclear. The mayor of Moscow has said authorities plan to set up 300 vaccination centres in the month of December and the plan is to get as many people in the capital inoculated as possible.Independent public opinion surveys suggest many Russians remain uncertain about the vaccine and whether they will actually take it. In early November, the polling group Levada Centre reported 59 per cent of Russians may refuse to get vaccinated.On Russian state TV, however, criticism or probing questions about any of the assumptions underlying the government's claims about Sputnik V have largely been absent. As is standard on TV talk shows, the discussion is framed in geopolitical terms.Their 60 Minutes program (no relation to the U.S. program of the same name) even cited a CBC News report by The National as purported proof of Western bias, with the host suggesting it was an example of "active propaganda" against Sputnik V. In fact, the report contained comments from Prof. Evans, the British expert, suggesting that the vaccine worked and was most likely effective. But his clips were cut from what was shown on Russian TV.