Russia answers tough FAQs on Covid-19 vaccine Sputnik V

Russia’s Covid-19 vaccine, Sputnik V, has been surrounded by scepticism since it was announced to the world. With the Russian government releasing it for public use recently, it has come up with a set of FAQs that attempts to quell fears regarding the vaccine that has not been through the Phase 3 clinical trials, Sputnik News reported.

Was the vaccine stolen?

No, the vaccine is not stolen. It uses a unique two-vector human adenovirus technology which no one else in the world currently has for Covid-19. Vectors are engineered viruses—unable to reproduce—which carry genetic material from the spike of a coronavirus. Our technology employs two different human adenoviral vectors, Ad5 and Ad26, for a first and a second injection. This technology helps to overcome pre-existing immunity to adenoviruses.

When will the Phase 1 and 2 clinical trial results be published?

The results of the trials were published in the medical journal The Lancet on September 4, which highlighted four key points-

1. Phase 1-2 of the clinical trials shows no serious adverse events for any of the criteria.
2. All participants of the clinical trial generated a stable humoral and cellular immune response. The level of virus-neutralising antibodies of volunteers vaccinated with Sputnik V was 1.5 times higher than the level of antibodies of severe Covid-19 patients who had recovered from Covid-19.
3. Specialists from the Gamaleya National Research Center of Epidemiology and Microbiology managed to prove the effectiveness of the human adenoviral vectors platform, despite concerns that vaccinated people could have pre-existing immunity to human adenoviruses. The optimal safe dosage has been determined, which achieved 100 per cent effective immune response in those vaccinated.
4. Through the use of two different vectors - based on human adenovirus serotypes Ad5 and Ad26 - in two separate shots, it is possible to achieve a more effective immune response. Whereas in the case of using the same vector for two shots, the immune system launches defence mechanisms and begins to reject the drug in the second injection. Thus, the use of two different vectors in the Sputnik V vaccine avoids a possible neutralising effect and provides for a stronger and more durable immune reaction.

Were there too few participants in Phase 1-2 trials?

The Sputnik V trial with 76 participants seems smaller in size compared to 1,077 people that, for example, AstraZeneca had in its Phase 1-2 studies. However, the trial was designed to be much more efficient and based on better assumptions. Overall, the number of people who received two injections in the Sputnik V trial exceeded the similar number in AstraZeneca trial by 4 times.

Will there be clinical trial on more people?

The post-registration studies involving more than 40,000 people started in Russia on August 26. Clinical trials in Saudi Arabia, United Arab Emirates (UAE), the Philippines, India and Brazil will begin this month. The preliminary results of Phase 3 trials will be published in October-November 2020.

Why has the Sputnik V vaccine already become eligible for emergency use registration?

Because of the very positive results of the Phase 1-2 trials and because the human adenoviral vector-based delivery platform has been proven the safest vaccine delivery platform over decades including through 75 international scientific publications and in more than 250 clinical trials.

Has anyone used similar technology for their vaccines?

Some other companies are using human adenoviral vector-based platforms for their Covid-19 vaccines. For example, Johnson & Johnson uses only Ad26 vector and China’s CanSino only Ad5 while Sputnik V uses both of these vectors. The work of Johnson & Johnson and CanSino validates the Russian approach.