Sputnik V demonstrates strong protection against Omicron variant, new study finds

New Delhi: A recent study shows that 2 doses of Sputnik V provide higher geometric mean titers (GMT) of virus neutralizing 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).

A leading peer-reviewed medical journal has published the results of 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 Gamaleya National Research Center of Epidemiology and Microbiology (Gamaleya Center).

An article by a team of 12 Italian and 10 Russian scientists led by Francesco Vaia, Director of the Spallanzani Institute and Alexander Gintsburg, Director of the Gamaleya Center, has been peer-reviewed and is available at: https://www.mdpi.com/2076-393X/10/5/817/htm

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 neutralizing activity against Wuhan variant.

According to the study’s findings, Sputnik vaccine provides for eliciting high titers of virus neutralizing antibodies to Omicron variant. Fast-spreading Omicron sub-variants BA.4 and BA.5 are currently causing surges of coronavirus cases in the United States, South Africa and 70 other countries.

The advantages of Sputnik V are the use of native S glycoprotein (spike protein without proline-stabilization and other modifications) and the use of a heterologous prime-boost vaccination regimen. The Pfizer vaccine utilizes the spike protein in a proline-stabilized form in contrast to Sputnik V. Proline-stabilization 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 neutralizing activity against this variant may be observed in the sera of Pfizer-vaccinated.

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.