Explained: What Sputnik V’s emergency use application may mean for India

Dr Reddy’s Laboratories has approached India’s apex drug regulatory body for emergency approval of Sputnik V, the company said Friday. The Indian Express looks at what this would mean for the country and its vaccination campaign against Covid-19.

What is Sputnik V?

This is a vaccine that uses two different human common cold viruses (adenovirus) that have been modified so that the gene causing the cold infection is removed and instead replaced with a code to make SARS-CoV-2’s ‘spike protein’ (the spikes seen on the surface of the virus, which allows it to penetrate the cells and replicate). The human adenoviruses then act as a vehicle to transport this code to the cells when a person is vaccinated, so that the body can develop an immune response in the form of antibodies to protect it in the event the real virus tries to infect.

The vaccine, named after the first Soviet space satellite, was developed by Moscow’s Gamaleya National Research Institute of Epidemiology and Microbiology.

Dr Reddy’s Laboratories has been testing the vaccine’s safety and ability to provide protection to the Indian population in phase 2/3 clinical trials on around 1,500 participants in the country. While phase 3 trials are still underway, they are expected to get over by February 21, according to the company.

What would an emergency approval of Sputnik V here mean for India?

If cleared by the regulator, Sputnik V would not only become the third Covid-19 vaccine to be approved here, but also a potentially more promising vaccine in terms of its ability to prevent symptomatic Covid-19 cases in those vaccinated.

This is because interim results published in The Lancet from ongoing phase 3 trials of Sputnik V in Russia showed the vaccine demonstrated an efficacy rate of 91.6 per cent. The efficacy of a vaccine shows its ability to prevent symptomatic cases of Covid-19 in the population being inoculated.

While this two-dose vaccine seems to be slightly less efficacious than the vaccines developed by Pfizer-BioNTech and Moderna-NIAID (which have an efficacy of around 95 and 94 per cent), it is so far the only candidate in India with a higher known efficacy than the vaccines currently in use.

India has approved the use of Bharat Biotech’s Covaxin and Serum Institute of India’s Covishield. While the efficacy of Covaxin, which is currently being administered in clinical trial mode, is not known, the efficacy of Covishield, according to its product insert, ranges between 53 to 79 per cent, depending on the duration between the first and the second dose. Based on a recent pre-print study of the AstraZeneca-University of Oxford vaccine (on which Covishield is based), this efficacy could be higher than 82 per cent if the second dose is given after over 12 weeks.

What happens now?

Once the application to the Central Drugs Standard Control Organisation is submitted, the request will be studied by a Subject Expert Committee. As part of the review process, the Hyderabad-headquartered firm said it will present the safety profile of the phase 2 study conducted with the vaccine as well as interim data of its ongoing phase 3 study.

The SEC will make recommendations about whether a restricted approval should be given to Sputnik V on an emergency basis in India.

Based on these recommendations, the Drug Controller General of India will take a call on whether Sputnik V will be allowed for use in India at this stage of the pandemic.