Russian Sputnik V Vaccine Claimed to be 95% Effective After 48-Day Second Dose

Russian Sputnik V Vaccine Claimed to be 95% Effective After 48-Day Second Dose

TrialSite has followed the Russian COVID-19 vaccine called Sputnik V. In a form of what could be perceived as a national competition or even so-called “Vaccine Nationalism” that country supported some highly questionable research tactics including pre-clinical testing on humans while  bypassing a Phase 3 clinical trial. These unorthodox and ethically challenged measures were taken to be first to declare that the vaccine candidate was “registered” meaning approved by the national health authorities in that country: implying the candidate was ready for distribution. Later on it was clarified that this was clearly an emergency use authorization. Of course, according to TrialSite point of view, this was more a marketing strategy than actual medical reality as the sponsor’s of the vaccine, both the state-owned National Research Center for Epidemiology and Microbiology and the Russian Direct Investment Fund (RDIF) sought to competitively position this product on the world market. After all, they faced intense competition from the Chinese vaccine makers and “Western” firms such as Moderna, Pfizer/BioNTech and AstraZeneca for access to nations and sites to host Phase 3 clinical trials. Domestically upon registration Russia embarked on a large-scale Phase 3 clinical trial involving 40,000 participants.  Now the RDIF (Russia’s sovereign wealth fund) reports that the Sputnik V vaccine is 95% effective according to a second interim analysis of clinical trial data. Interestingly and perhaps not surprisingly, this matches the effectivity rate of western firms such as Moderna (94.5%) and Pfizer/BioNTech (95%). In a competitive push, the RDIF also announced that the two-dose vaccine would be offered on the international market for a price point below $10 per dose while absolutely free for the Russian population.

TrialSite links to the original news source (RDIF) and highlights that the group declared its calculations were premised on preliminary data secured 42 days after the first dosing during the clinical trial and backed by both the Gamaleya Institute and the RDIF.

The official press release touted that at 28 days after the first dose the vaccine was 91.4 percent effective, based on 39 actual cases. However, they noted that 42 days thereafter with consumption of the second dose the efficacy rate was reported at 95 percent. Interestingly the actual number of COVID-19 cases used for this last calculation were not disclosed. Alexander Gintsburg, Gamaleya’s director was quoted in a carefully crafted statement, “The second analysis was conducted a week after volunteers got the second dose, meaning that their bodies have partially reacted to both doses.”

Concerns with Sputnik V

TrialSite has detailed the development path of Sputnik V, albeit from afar and mostly from either international or Russian press. And TrialSite has disclosed its own subjective, Western-based bias throughout.  It’s certain that the sponsors of this vaccine took unorthodox measures, to say the least, to accelerate this vaccine candidate. From supporting the preclinical human testing to a questionable compression of Phase 1 and 2 studies to totally bypassing Phase 3 to declare the product “registered” all raised serious eyebrows not only in the West but also among Russia’s clinical research professional community.

Hopes for the World

Although at least in the West scientists are more skeptical about Sputnik (for the reasons TrialSite has covered) if the candidate turns out, after peer reviewed results to be highly effective, this can only be celebrated as another positive data point that the world’s community will overcome COVID-19. Afterall with great recent news associated with Moderna and Pfizer/BioNTech, the virus knows no national boundaries.

Perhaps the Russian use of two different vectors based on the human adenovirus, which according to RDIF allows for longer-term immune response as compared to vaccines using one and same vector for two doses, may actually work well. Only time and sufficiently peer reviewed data will tell. The more highly effective, high quality vaccines are on the world market the better. This will serve to accelerate the end of this horrific pandemic; an event of the century causing untold health, economic and social damage to societies and communities around the world. 

The Summary

RDIF summarized the most recent findings which can be accessed here. Note it’s claimed that the final results will be published in an international peer reviewed journal. TrialSite awaits that day. When these Russian agencies do disclose the data they should be completely transparent about the measures they took to accomplish their results. More transparency may not equate to complete Western acceptance but it’s the right thing to do.


  1. I strongly believe in published by the russian side data.

    You bring : on preliminary data secured 42 days after the first dosing during the clinical trial and backed by both the Gamaleya Institute and the RDIF.

    I know the russian way of doing things even scientific, more than well, at least that is what I thing.
    and although I have to agree with your statement, that can obey to very different extra scientific investigation situations. In other words You are right about 42 days after, but the collected data can be 100% genuine, reliable and backed up by real science