MOSCOW, March 23. /TASS/. Repeat vaccination against COVID-19 with Russia’s Sputnik V vaccine is possible, and it can even be more effective than initial inoculation, head of the Gamaleya Research Center for Epidemiology and Microbiology, which developed the vaccine, Alexander Ginzburg told reporters on Tuesday.

"The data provided by a number of research works carried out both in our country and abroad point to the fact that the preexisting immunity to adenoviruses practically does not affect the development of an immune response after immunization with vaccines based on adenovirus vectors. Moreover, it was proven that revaccination with adenovirus vectors is possible without losing immunogenicity to the target pathogen. Thus, not only is revaccination against Sputnik V possible, it can even be more effective that initial vaccination," Ginzburg said.

According to the developer, research has shown that revaccination six months after the initial one-off vaccination helps raise the antibody response among 100% of volunteers despite their potential immunity to the adenovirus vector.

"Moreover, the pre-existence of immunity to human adenoviruses increases the formation of cell immunity, which is a key factor in the protection against coronaviruses, and it practically does not affect the formation of a humoral immune response to the target pathogen," he noted.

Earlier on Tuesday, Deputy Director for Clinical and Analytical Work at the Central Scientific Research Institute of Epidemiology Natalya Pshenichnaya stated that people vaccinated with Sputnik V are unlikely to be able to get revaccinated with it, but they can use other vaccines, such as Epivaccorona or Covivac. Later, she clarified that revaccination with Sputnik V is possible, however, it is up to the attending physician to decide which vaccine should be used for revaccination.