An international team of Mongolian, American and Canadian scientists investigated the effect of Pfizer, Astrazeneca, Sputnik V and Sinopharm vaccines on antibody titer in a small sample of Mongolians, where all four drugs are registered.
The best result was shown by the Pfizer vaccine, the second place was taken by Astrazeneca, the third – by Sputnik V, the least amount of antibodies was detected in those vaccinated with Sinopharm. Research results published in Cell Host and Microbe.
The researchers evaluated the effectiveness with which antibody-containing blood plasma samples block the binding of the virus model to the ACE2 receptor, through which the virus enters cells.
The reasons for the differences in immune responses between types of vaccines are the subject of research. These are likely to include factors such as the amount of active ingredient in each dose and the interval between receiving the first and second injections, the study authors say.
In the Russian Direct Investment Fund, which is engaged in the supply of “Sputnik V” abroad, a comparison named incorrect, stating that the participants in the study vaccinated with the Russian vaccine were, on average, 10 years older than those vaccinated with other drugs. In addition, according to Russian scientists, antibodies in the study participants were measured after a longer period of time after vaccination.