The Russian Sputnik V vaccine developed is 91.6 percent effective in protecting against symptomatic COVID-19 – on a par with currently approved western jabs, according to a peer-reviewed study published in The Lancet Tuesday.
The data are from a Phase 3 study, with nearly 20,000 participants in various hospitals and clinics in Russia participating in the two-dose scheme. From 21 days after the first dose, there were 16 cases of symptomatic COVID-19 in the vaccine group versus 62 cases in the placebo group, the researchers reported. There were no cases of “moderate or severe” coronavirus infections in the vaccinated group 21 days after the first dose.
The clinical trial also looked at people over 60, finding that the jab was 91.8% effective, based on 2,144 participants.
The issue of efficacy in the elderly has followed the debate over the Oxford / AstraZeneca vaccine due to a lack of data. Last week, German experts recommended that shooting be restricted to children under 65 until more data is collected.
The Sputnik V vaccine is based on an adenoviral vector, which involves using a modified version of the common cold to induce cells to produce the spike protein found in the coronavirus. The body then produces antibodies that target the protein, giving immune protection. The Russian-made jab differs from the Oxford / AstraZeneca shot – which is based on similar technology – in that it uses two different viruses in each shot.
The study authors say the two-part vaccine strategy can “help create a more powerful immune response” because it reduces the risk of the body developing resistance to the injection, which would otherwise decrease the effectiveness of the second injection.
However, the study also notes that because coronavirus cases were detected only when participants reported symptoms and were tested, the effectiveness covers only symptomatic cases of coronavirus. More research is needed to assess effectiveness for cases without symptoms, the study concluded.
In the EU, only Hungary has given its approval to use the Russian injection, although negotiations with the European Medicines Agency are ongoing. Serbia and Belarus have given the green light for the vaccine. A spokesman for the Russian Direct Investment Fund, which is responsible for promoting Sputnik globally, said he plans to start the jab review with EMA this month.
The clinical trial is in progress and aims to include around 40,000 participants in total.
In a written commentary, Ian Jones, a professor at the University of Reading, and Polly Roy, a professor at the London School of Hygiene & Tropical Medicine, noted that “the result reported here is clear”, despite all criticisms about Sputnik’s lack transparency and the “indecorous rush” of its development.
“Another vaccine may now join the fight to reduce the incidence of COVID-19,” they said.