Russian Coronavirus Vaccine Maker Studying 3rd Booster Shot May 5, 2021 A man receives an injection of the EpiVacCorona vaccine against Covid-19 at municipal polyclinic in St. Petersburg. Peter Kovalev / TASS
The makers of Russia’s second approved coronavirus vaccine EpiVacCorona are studying third doses to boost recipients immune response, a senior scientist said Wednesday.
Approved last fall and added to Russia’s mass immunization program last month, EpiVacCorona has come under scrutiny after a group of late-trial study participants claimed that it does not produce an immune response. Early-trial results published in a Russian medical journal this spring disputed that claim, saying that all adults involved in phase one and two trials had developed antibodies.