The efficacy of Russia’s EpivacCorona coronavirus vaccine, according to the provisional results documented in the quality control review of the third phase of the vaccine’s clinical trials, is 79%, the Izvestia daily reported on Thursday, citing Clinical Research Laboratory, an independent research organization, APA reports citing TASS.
According to the newspaper, 79% of volunteers and 11.6% of those who had received placebo developed IgG coronavirus antibodies on the 42nd day after vaccination with EpivacCorona. According to the Vector Center, the vaccine’s developer, this is the vaccine’s immunological, but not epidemiological efficacy. These indices are calculated differently, it noted.
"It is important to stress that the 79% of volunteers with IgG antibodies indicated the vaccine’s immunological efficacy. It should not be confused with the epidemiological efficacy of the vaccine which is based on other data and is calculated according to a special formula. When we speak about a vaccine’s efficacy we mean its epidemiological efficacy," Tatiana Nepomnyashchikh, a deputy director of the Vector Center, explained.
The study of EpivacCorona’s efficacy and safety involved 2,999 volunteers older than 18 (phases 3 and 4). It was initially planned to involve 3,000 volunteers but one person withdrew from the trials. As many as 2,253 people were inoculated with EpivacCorona and 746 received placebo. A testing system developed by the Vector Center was used to detect antibodies.
A vaccine’s efficacy is made up of its immunological and epidemiological efficacy. The former takes into account the development of specific antibodies whereas the latter is about the protection of those inoculated against the disease.