Sputnik V vaccine: technology, distorted efficacy?

Developed by the Gamaleya Institute, the Russian vaccine Sputnik V would be 91.6% effective against Covid-19. A figure that has been questioned by Australian researchers. Its review in Europe began in March 2021 but as of 2022 it is still stalled.

Russia produced four vaccines against Covid : the Sputnik V (the first), the Sputnik Light (dose), EpiVacCorona and CoviVac. None have been endorsed by the World Health Organization (WHO). Same thing in France. However Sputnik V was nevertheless approved in several countries of the world: in Russia, in Belarusin Algeria, in Argentinain BoliviaSerbia, Palestine, VenezuelaParaguay, Turkmenistan, Brazil, Hungary (only EU country having validated it), in the United Arab Emirates, in Iran and in Republic of Guinea. If the Russians claimed a vaccine more than 91% effective against Covid, Australian researchers questioned this figure in June 2022: “There are signs, and many reasons to think, that someone could have manipulated this data after the end of the study assured Dr. Kyle Sheldrick to the British site of the Daily Mail. I think the vaccine probably works I don’t think it was all made up but I think it was done in a massive rushhe concluded in an article published in the American Journal of Therapeutics. EMA’s Committee for Medicinal Products for Human Use (CHMP) has launched a review of Sputnik V in March 2021. The EMA assesses Sputnik V’s compliance with the usual European standards for efficacy, safety and quality. As of September 2022, this review has stalled.

According to information published by the Russian National Center of Epidemiology and Microbiology Gamaleya, the creator of the vaccine, this name was assigned in tribute to the first satellite launched by the USSR in 1957. “The launch of Sputnik-1, in 1957, gave a new impetus to space exploration worldwide, creating the so-called ‘Sputnik Moment’ for the global community”, explains the Gamaleya Institute on its website dedicated to the vaccine. The “V” was added for vaccine. Sputnik V began to be distributed in 70 Moscow clinics on December 5, 2020 for the launch of the vaccination campaign.

According to a study published by the British medical journal The Lancet Tuesday, February 2, 2021, and validated by independent experts, the Russian vaccine Sputnik V reduced by 91.6% the risk of contracting a symptomatic form of Covid-19. These results are from phase 3 clinical trials conducted between September and November 2020 out of 19,866 attendees. They were made in Russia, Belarus, the United Arab Emirates, India and Venezuela. The volunteers received two doses of vaccine or a placebo 21 days apart. In total, 16 of the 14,964 volunteers who received both doses of the vaccine (0.1%) tested positive compared to 62 of the 4,902 who received the placebo (1.3%). In the days following the administration of the second dose, a PCR test was only carried out in people with symptoms of Covid-19. These results corroborate the initial data announced by Russia last fall, which had aroused the mistrust of the international scientific community. However, researchers point to the fact that the effectiveness of Sputnik V relates only to symptomatic cases. Sputnik V also seems effective on people over the age of 60based on an analysis of more than 2000 people. “Vaccine efficacy for the elderly is 91.8% and does not differ statistically from that of the 18-60 age group”, specifies the manufacturer on its website. In other words, Sputnik V would be among the most effective vaccines against Covid-19 with those of Pfizer/BioNTech and Moderna (95% and 94.1% respectively). Australian researchers questioned this claim in June 2022: “There are signs, and many reasons to think, that someone could have manipulated this data after the end of the study assured Dr. Kyle Sheldrick to the British site of the Daily Mail.

Like the vaccine developed by AstraZeneca/Oxford, Sputnik V is a so-called “viral vector” vaccine. But unlike the vaccine from the British laboratory, which is based on a chimpanzee adenovirus, the Russian vaccine uses two human adenoviruses which differ between the first and the second injection. These adenoviruses have been modified to contain the gene to make the SARS-CoV-2 spike protein. The person’s immune system will treat this spike protein as foreign and produce natural defenses – antibodies and T cells – against this protein. If the vaccinated person later comes into contact with SARS-CoV-2, the immune system will recognize the spike protein on the virus and be ready to attack it. According to the manufacturer, this technique makes it possible to obtain a better immune response. “Human adenoviruses are considered to be among the easiest to manipulate in this way and have therefore become very popular as vectors”, indicates the Russian National Center of Epidemiology and Microbiology Gamaleya on its website dedicated to the vaccine. Furthermore, these human adenoviruses are safe since they have been around for a very long time and are well known: they are the ones that cause simple colds.

The world’s first vaccine registered on the human adenovirus vector platform, Sputnik V is the only anti-Covid vaccine to be composed of two different vectors against sars-CoV-2. The first injection adenovirus vector usually causes acute respiratory viral infections. A gene coding for the S protein, the tip of the virus through which Sars-CoV-2 enters our cells, is inserted into each vector. The body can then begin to defend itself. The second doseadministered 21 days after the firstincludes another adenoviral vector responsible for stimulating the immune response.

Few data are available concerning the side effects of the Sputnik V vaccine. However, the Gamaleya laboratory ensures that its serum has demonstrated an excellent safety profile. “Most adverse reactions (94%) are mild and include flu-like illnesses, skin reactions at the injection site, headache or asthenia,” he says on his official website. Similarly, according to the Independent Data Monitoring Board, no serious adverse events were observed, and no cases of severe allergy or anaphylactic shock were reported.

For now, the vaccine is recommended up to the age of 60. Sputnik V is contraindicated for people with certain underlying medical conditions, pregnant women, and those who have had respiratory disease within the past two weeks. However, when the European Medicines Agency (EMA) has granted marketing authorization (AMM), the Haute Autorité de Santé will issue its own recommendations for the French population.

Sources:

Sputnik V, About the vaccine, Gamaleya Institute

Safety and efficacy of an rAd26 and rAd5 vector-based heterologous prime-boost COVID-19 vaccine: an interim analysis of a randomized controlled phase 3 trial in Russia, The Lancet, 2 February 2021

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