According to an announcement by the Gamaleya National Research Center of Epidemiology and Microbiology (Gamaleya Center) and the Russian Direct Investment Fund (RDIF, Russia’s sovereign wealth fund, investor in Sputnik V and Sputnik Light coronavirus vaccines), a unique independent comparative study conducted at the National Institute for Infectious Diseases Lazzaro Spallanzani (Italy) by a joint team of researchers of the Institute and the Gamaleya Center showing that 2 doses of Sputnik V provide more than 2 times higher geometric mean titers (GMT) of virus neutralising antibodies to the Omicron variant of COVID than 2 doses of Pfizer vaccine (2.1 times higher in total and 2.6 times higher 3 months after vaccination).

The study was conducted in Spallanzani Institute in the equal laboratory conditions at the Italian Spallanzani Institute on comparable groups of sera from individuals vaccinated with Sputnik V and Pfizer, with no statistically significant difference in neutralising activity against Wuhan variant.

The advantages of Sputnik V are the use of native S glycoprotein (spike protein without proline-stabilisation and other modifications) and the use of a heterologous prime-boost vaccination regimen. The Pfizer vaccine utilises the spike protein in a proline-stabilised form in contrast to Sputnik V. Proline-stabilisation and other modifications may move an immune response predominantly to the actively mutating receptor-binding domain (RBD) of spike protein. In the Omicron variant, a substantial number of mutations were registered precisely in RBD, which is why such a significant drop in neutralising activity against this variant may be observed in the sera of Pfizer-vaccinated.

Vaccine boosts with “mix & match” approach

Boosting with Sputnik Light as part of the “mix & match” approach may help address the lower efficacy of mRNA vaccines against Omicron as well as the documented, quickly waning, efficacy of mRNA vaccines against COVID-19. Partnerships between adenoviral and mRNA vaccines could provide for stronger protection against Omicron and other variants.

Results of the study in Italy confirm Sputnik V offers the strongest protection against Omicron. The adenoviral platform has shown high efficacy in fighting mutations of COVID previously. Partnership of different platforms is the key and heterologous (“mix & match”) boosting with Sputnik Light will help strengthen efficacy of other vaccines in light of combined Delta and Omicron challenge.”

– Kirill Dmitriev, CEO of the Russian Direct Investment Fund

Sputnik Light has already shown strong results as a booster in “mix & match” trials in Argentina. A combination of Sputnik Light with vaccines produced by AstraZeneca, Sinopharm, Moderna and Cansino, conducted in 5 provinces (City and Province of Buenos Aires, as well as Córdoba, La Rioja and San Luis) has demonstrated that Sputnik Light induces stronger antibody and T-cell response as compared to a homologous regimen (two shots of the same vaccine). Each “vaccine cocktail” combination with Sputnik Light provided higher antibody titer on the 14th day after administering a second dose when compared to original homologous (same vaccine as first and second dose) regimens of each of the vaccines.

Sputnik Light as a booster significantly increases virus neutralizing activity against Omicron, which is comparable to titers observed after Sputnik V against wild-type virus, associated with high levels of protection. The study results were summarised in an article available at: www.medrxiv.org/content/10.1101/2021.12.17.21267976v1

Editor’s note: Sputnik V is only recognised in 73 countries as a valid COVID-19 vaccine. It is not recognised in Singapore and Malaysia. Please consult a medical expert if you are considering receiving the Sputnik V as a booster.

Images: Russian Direct Investment Fund