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Sputnik V, the Russian vaccine against SARS-CoV-2

The first vaccine registered to fight the pandemic caused by the SARS-CoV-2 virus was the Russian vaccine, better known as Sputnik V. The vaccine is based on the use of human adenovirus vectors that transport the protein that the immune system is wanted to act on to generate immunity.

Introduction

The COVID-19 disease was first reported in  Wuhan, China,in lateDecember 2019, although its origin is still under discussion. The disease is an acute respiratory illness that varies in severity from mild to severe, with death in some cases. Many infected people are asymptomatic. Since the end of January 2020, COVID-19 cases have been reported in more than 200 countries around the world. On  March 11, 2020,the Health Organization(WHO)describedthe spread of COVID-19 as a pandemic.

The causative agent of COVID-19 is the virus called severe acute respiratory syndrome coronavirus 2  (SARS-CoV-2). SARS-CoV-2 can be transmitted in many ways, with the main route of transmission being contact with infected people (e.g., through secretions, especially droplets). As of August 29, 2021, there have been more than  217 million laboratory-confirmed cases of SARS-CoV-2 infection and more than  4.5 million deaths.

The Gam-COVID-Vac, nicknamed Sputnik V by the Soviet satellite Sputnik 1, the first artificial satellite launched into space, is the first COVID-19 vaccine recorded in the world. To date it has been approved in 70 countries with a potential to reach 4 billion people.

Vaccine developers and description

The developers of the vaccine are Gamaleya Research Institute  and the Health Ministry of the RussianFederation. The National Center for Epidemiology and Microbiology in Gamaleya is a leading research institution in the world. The center was founded in 1891 as a private laboratory. Since 1949 it has been named after  Nikolai Gamaleya,a pioneer in Russian microbiology studies.

It uses a viral vector. The number of doses is 2 inoculations in a space of 21 days. The efficacy of the vaccine is  97.6%,according to the analysis of data on the incidence of coronavirus among Russians vaccinated with both doses of the vaccine between December 5, 2020 and March 31, 2021.

Phase 1 and 2 clinical trials for the vaccine were completed on August 1, 2020. The results of the phase 3 clinical trial were published in Russia in the journal Lancet on February 2, 2021. Phase 3 clinical trials of Sputnik V have also been successful in the United Arab Emirates, India, Venezuela and Belarus.

How the Sputnik V vaccine works

The Sputnik V vaccine is based on a well-studied and tested human adenovirus vector platform; these adenoviruses cause the common cold and have affected humanity for thousands of years.

Sputnik V was the first coronavirus vaccine to use a heterogeneous booster approach based on 2 different vectors for 2 vaccine injections. This approach generates more sustainable immunity compared to vaccines that use the same administration mechanism for both injections. The following figure explains how it works.

sputnik V
Figure 1. Source https://sputnikvaccine.com/about-vaccine/

It therefore uses a non-dangerous vector for the body that does not create new copies of the virus and that serves as a means of transport for the gene that codes for the S protein. There are two vaccinations. In the first, Adenovirus AD26 is used as a vector, while in the second, Adenovirus AD5 is used as a vector. The first vaccine generates immunity, while the second generates long-term immunity.

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