The Sputnik V vaccine would be 91.6% effective against symptomatic forms of the coronavirus. A study was conducted by independent experts and published in the medical journal The Lancet Tuesday February 2. These results allow, according to the researchers, to classify the Russian vaccine among the means of combating Covid-19, in the same way as the Pfizer / BioNTech, Moderna or AstraZeneca vaccines. “The development of the Sputnik V vaccine has been criticized for its haste, the fact that it has skipped steps, and a lack of transparency. But the results reported here are clear and the scientific principle of this vaccination has been demonstrated, ”said two British specialists, Professors Ian Jones and Polly Roy, in a commentary attached to the study of Lancet. This “means that an additional vaccine can now join the fight to reduce the incidence of Covid-19”, insisted these researchers, who were not themselves involved in the study.
These first verified efficacy results corroborate Russia’s initial assertions, which were received with suspicion last fall by the international scientific community. At this stage, they seem to rank Sputnik V among the best performing vaccines, along with those from Pfizer / BioNTech and Moderna (around 95%), which however use a different technology (messenger RNA). In recent weeks, voices have started to rise in Europe for the European Medicines Agency (EMA) to quickly assess Sputnik V, already used in Russia and in a few countries (including Argentina and Algeria).
New research needed for asymptomatic cases
The results published in The Lancet come from the last stage of clinical trials of the vaccine, phase 3, which involves nearly 20,000 participants. As always in such cases, these results come from the team that developed the vaccine and then conducted the trials, and they were then submitted to other independent scientists for publication. They show that Sputnik V reduces the risk of contracting a symptomatic form of Covid-19 by 91.6%.
Participants in the September to November trial all received two doses of the vaccine or placebo three weeks apart. Each time, this was accompanied by a PCR test. In the days following the administration of the second dose, a PCR test was only performed in people who developed symptoms. A total of 16 volunteers out of 14,900 who had received both doses of the vaccine tested positive (0.1%), compared with 62 out of 4,900 who received placebo (or 1.3%).The authors point to a limit, however: insofar as the PCRs were only carried out “when the participants declared to have symptoms of Covid, the analysis of the effectiveness relates only to the symptomatic cases”. “Further research is needed to determine the efficacy of the vaccine on asymptomatic cases and on transmission” of the disease, continues The Lancet in a press release.
Sputnik V uses the same technique as AstraZeneca
In addition, based on some 2,000 cases of people over 60 years, the study considers that the vaccine seems effective in this age group. Finally, partial data seem to show that it protects extremely well against moderate to severe forms of the disease.
Russian Sputnik V is a “viral vector” vaccine: other viruses are taken as a basis, rendered harmless and suitable for combating Covid. This is also the technique used by the AstraZeneca / Oxford vaccine, 60% effective according to the European Medicines Agency (EMA).
But while AstraZeneca’s vaccine is based on a single chimpanzee adenovirus, Russian Sputnik V uses two different human adenoviruses for each of the two injections. According to its designers, using a different adenovirus for the booster than the first injection could provoke a better immune response.