Some Russians get extra COVID-19 shots, Sputnik V developers say no need

Moscow: Some Russians who have taken COVID-19 antibody tests and found their antibodies have fallen are having third and fourth shots of the Sputnik V vaccine, but researchers in the country suggest they are unnecessary.

Revaccination in effect simulates getting the disease so that the body develops more antibodies to fight it. Researchers have said an immediate rise in antibodies seen by those getting a third or fourth shot suggests they did not need revaccination. Sputnik V was one of the first vaccines widely used in a population, so Russia's findings on revaccination will be closely watched elsewhere. The question of how long a vaccine offers protection against COVID-19 will be vital as countries gauge when or whether revaccination will be needed.