The Russian CoviVac vaccine against COVID-19 is suitable as a booster dose for people who initially received other vaccines, Aydar Ishmukhametov, the head of the Chumakov research center, said on 18 November.

"We believe that ... for the formation of immunity, it is quite possible to combine vaccines on different platforms," Ishmukhametov said at the online meeting of the Russian Academy of Sciences.

"And this is currently confirmed by international approaches," he added.