India announced that it had approved Dr Reddy's Laboratories appeal for the Russian Sputnik V COVID-19 vaccine to be used under emergency use authorization on Tuesday. The Russian vaccine was met with scepticism as well as criticism for fast tracking its scientific and regulatory mechanisms to approve this vaccine for use in August 2020.
Scientists from the Gamaleya Institute of Epidemiology in Russia who developed the vaccine, eventually published their findings in the British journal Lancet wherein they stated that the vaccine shows close to 91.6% efficacy against SARS-CoV-2. While three participants in the vaccine arm of the trial died, the researchers stated that this was not linked to the vaccine. About 45 of the 16,427 (0.3%) participants who received the vaccine reported severe adverse events. However, the Independent Data Monitoring Committee ruled out the vaccine as a cause of those events.
The Russian Direct Investment Fund that is funding the vaccine has already signed distribution contracts with several countries, has also chosen six manufacturers to produce the vaccine in India. Dr. Reddy's Laboratories, Gland Pharma, Hetero Biopharma, Virchow Biotech, Panacea Biotec and Stelis Biopharma are the six manufacturers who can produce close to 600 million doses in a year. Except for Dr Reddy's Laboratories, the other five organisations are yet to approach India's drug regulator.
With its high efficacy results not being disputed, scientists are now convinced that the vaccine will have an important role to play in combating COVID-19. Polly Roy, Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK, who was not a part of the clinical trials for Sputnik noted in the Lancet that the development of the Sputnik V vaccine has been criticised for unseemly haste, corner cutting, and an absence of transparency. But since the outcome reported is clear and the scientific principle of vaccination is demonstrated, which means another vaccine can now join the fight to reduce the incidence of COVID-19.
Roy also added that the suggested lessening of disease severity after one dose is particularly encouraging for current dose-sparing strategies.
An article in the British Medical Journal also talks about how scientists are still unaware about all the possible methodologies used in the study as the researchers have not been transparent but are welcoming the results shared in February 2021.
What Technology Does The Vaccine Use?
Just like the Oxford-AstraZeneca vaccine, even Sputnik uses common cold causing adenoviruses as viral vectors that will carry the SARS-CoV-2 gene for its glycoprotein S. But unlike the other vaccine, Sputnik uses two separate vectors.
While the first dose has the rAd25 adenovirus, the second shot given after 21 days has the rAd26 adenovirus. The scientists chose two different vectors as they were worried that the human body could potentially generate an immune response against the adenovirus instead of the gene.
Stored at -18 or at 2-8ºC, antibodies against SARS-CoV-2 are seen close to 20 days after the second shot is administered. The paper, however, does not discuss the nature of the severe adverse events or the reasons for the death, thus its side effects are still unclear.