Leading US vaccine scientist explains why Sputnik V beats Pfizer against Omicron

Sputnik V produces a better neutralizing antibody response to Omicron than the mRNA vaccines, Professor Hildegund Ertl, one of the top US vaccine specialists, said, according to a statement posted on Sputnik V Twitter page on Monday.

The vaccine and immunotherapy researcher working at the Wistar Institute located in Philadelphia, Pennsylvania, believes that the Russian jab’s adenoviral vector provides for a “far longer” expression of antigen than any of the mRNA vaccines. This results in “stimulation of durable antibody-secreting cells,” the statement said.

“Overall, these results are extremely promising,” professor Ertl said while commenting on the results of a fresh comparative study presented by a joint Russian-Italian team working at the Spallanzani Institute, Italy’s leading research institute for infectious diseases. The team published a preprint of the study last week.

The researchers at the Spallanzani Institute studied the serum samples from individuals vaccinated with Sputnik V and Pfizer and found that the Russian jab produces twice as high level of virus neutralizing antibodies against Omicron as the US vaccine, which, in turn, means better protection against the virus. 

“Among all samples, 74.2% of Sputnik V-vaccinated sera were able to neutralize Omicron vs 56.9% for Pfizer-vaccinated,” RDIF said in a statement, citing the study results. 

It is also said that the Russian jab demonstrates a significantly smaller reduction of the virus neutralizing activity against Omicron in comparison to the original Covid-19 strain. Sputnik V shows a roughly eightfold reduction in its effectiveness against the new strain, while the Pfizer/BioNTech jab is 21 times less effective. 

Professor Ertl is one of the leading researchers behind the development of vaccines for a wide range of diseases, including Covid-19, AIDS, chronic viral infection and even some forms of cancer. She believes that the disparities in the virus neutralizing response demonstrated by the two jabs might “reflect differences in the antigen structure and duration of its expression.”

She also pointed to the fact that Sputnik V produced high antibody titers against the original “wild” Covid-19 strain, which remains stable for six months after vaccination, while the protection level induced by the mRNA vaccines declined by 10 times over the same period. 

The Italian study’s results have also been welcomed by Ancha Baranova, a molecular biology specialist at the George Mason University’s Institute for Biohealth Innovation. 

According to Baranova, Sputnik V provides a wider pool of antibodies to the spike protein than the vaccines used in the US. The molecular biologist explained that American vaccine developers artificially changed the configuration of the Covid-19 spike protein for their vaccines, thus making them capable of producing antibodies narrowly tailored to it. 

Such changes made these vaccines less effective at detecting and neutralizing Omicron, which has a highly mutated spike protein and is capable of evading immune response to a certain extent.

Sputnik V’s researchers did not introduce any specific changes into the Covid-19 protein used in their vaccine.  That, in turn, provided for a more “diverse” antibody response, Baranova explained, adding that the immune system of those vaccinated with Sputnik V produces “more various antibody types,” thus increasing a chance of successful virus neutralization. 

Alexander Gintsburg, the head of the Gamaleya National Center for Epidemiology and Microbiology, has praised the results of the joint study that researchers from his center conducted with the Italian specialists. He said these results confirm the data obtained by his team in a separate study published in late 2021, adding that “hard scientific data proves Sputnik V has higher virus neutralizing activity against Omicron as compared to other vaccines.”