Moscow [Russia], May 24 (ANI): Gamaleya National Research Center of Epidemiology and Microbiology on Wednesday said that Sputnik V demonstrated strong protection against Omicron variant of COVID-19.

A comparative study conducted at the Italian Spallanzani Institute, the Italian research institute for infectious diseases, by a joint Italian-Russian team of researchers representing the Institute and the Gamaleya Center show that the Sputnik V coronavirus vaccine demonstrates higher titers of virus-neutralizing antibodies to Omicron (B.1.1.529) variant than 2 doses of Pfizer vaccine (2.1 times higher in total and 2.6 times higher 3 months after vaccination), Gamaleya Center said in a statement.

The study was published in 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.

According to the findings, the 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 the 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.

The results were published in the Vaccines peer-reviewed leading medical journal.

The study demonstrates that Sputnik V neutralizes the Omicron variant by inducing robust antibody response associated with high levels of protection.

According to the Gamaleya Center, among the top quartile of individuals with high RBD-specific IgG antibodies, 100 per cent of those vaccinated with Sputnik V were able to neutralize Omicron variant in comparison to 83.3 per cent of individuals vaccinated with Pfizer. Furthermore, among all samples, 74.2 per cent of Sputnik V-vaccinated sera were able to neutralize Omicron vs 56.9 per cent for Pfizer-vaccinated.

The study discusses several reasons for Sputnik V eliciting stronger virus neutralizing antibodies against Omicron including -- Sputnik V develops a wider pool of antibodies to different epitopes in contrast to Pfizer vaccine, which utilizes the spike protein in a proline-stabilized form directed mainly to the specific epitopes, which were highly affected by the mutations in the Omicron variant.

Heterologous prime-boost vaccination regimen of Sputnik scheme and better mimicking of adenoviral vaccine platform of the infection.

The data supports the results of the recent laboratory study by the Gamaleya Center published in MedRxiv[1] demonstrating that Sputnik V induces robust neutralizing antibody response to Omicron variant, which is further strengthened by Sputnik Light booster.

Sputnik Light is a universal booster to other vaccines. Sputnik V has been authorized in 71 countries with a total population of over 4 billion people, and Sputnik Light in more than 30 countries. (ANI)