Putin has claimed that the vaccine works “quite effectively”, and “forms a stable immunity” against the infection. (AP)

The Indian embassy in Moscow is in touch with the Russian medical research institute that has developed the world’s first Covid-19 vaccine to be cleared for use by the public, top government sources told The Indian Express.

Russian regulators last week greenlighted the Sputnik V vaccine developed by the Moscow-based Gamaleya Research Institute of Epidemiology and Microbiology, and President Vladimir Putin announced that one of his daughters had already been inoculated with it.

“The Indian Mission is engaging separately with the Russian side through our embassy in Moscow. We are now awaiting the safety and efficacy data of this vaccine for Covid-19,” a source said.

Western experts have been sceptical about the Russian claim, given the speed and secrecy with which the Gamaleya candidate has been given regulatory approval. Developing a vaccine is a complex and lengthy process, and the candidate must pass extensive field trials before it is cleared for human use. The Sputnik V candidate has been approved without being put through final phase 3 human trials.

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Putin has claimed that the vaccine works “quite effectively”, and “forms a stable immunity” against the infection.

The official Sputnik V website, run by the Russian sovereign wealth fund Russian Direct Investment Fund (RDIF), says phase 1 and 2 clinical trials of the vaccine were completed on August 1, 2020, and the vaccine received a registration certificate under “emergency rules” from the Russian Ministry of Health on August 11.

“Phase 3 clinical trial involving more than 2,000 people in Russia, a number of Middle Eastern (UAE and Saudi Arabia), and Latin American countries (Brazil and Mexico)”, the website says, “will start on August 12”.

Gamaleya is yet to publish the results of phase 1 and 2 of the clinical trials. In phase 1, the vaccine candidate is given to a small group of people, and scientists measure the antibodies it triggers in the recipients. This process takes about three months and, if found safe, the trial moves to the next phase.

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The vaccine is given to several hundred people to assess reactogenicity (ability to produce common, adverse reactions), immunogenicity (ability to provoke an immune response), and safety. This stage of trials has been shortened in the development of Covid-19 vaccines – and as many as six candidates are currently in phase 3 of human trials.

According to the Russian study design published in the clinical trial registry, researchers will assess the adverse events for an average 180 days, and measure the change in antibody levels against the SARS-CoV-2 glycoprotein on days 0, 14, 21, 28, and 42.

The researchers will also assess the concentration of the neutralising antibody on days 0, 14, 28, and 42, and the change in the cellular immunity level, specifically T-cell immunity, on days 0, 14, and 28.

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“The high efficacy of the vaccine was confirmed by high precision tests for antibodies in the blood serum of volunteers (including analysis for antibodies that neutralize the coronavirus), as well as the ability of the immune cells of the volunteers to activate in response to the spike S protein of the coronavirus, which indicates the formation of both antibody and cellular immune vaccine response,” the Sputnik V website says.

A Reuters report quoted Kirill Dmitriev, CEO of RDIF, as saying Russia had received requests for a billion doses of the vaccine from other countries, and that international agreements had been secured to produce 500 million doses annually. Clinical trials were expected to start soon in the UAE and the Philippines, and Philippine President Rodrigo Duterte would participate personally, Dmitriev said.

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