4. Discussion
poliomyelitis, tick-borne encephalitis
CORONAVIRUS, POLIOMYELITIS, TICK-BORNE ENCEPHALITIS
According to the WHO, so far, 18 inactivated vaccines against COVID-19 have passed Phase I-II clinical trials worldwide, of which five have also passed Phase III trials (WHO, 2023). Successful clinical trials of 11 inactivated vaccines demonstrate that they are highly useful in the prevention of severe COVID-19 cases in the situation of a drastic global shortage of COVID-19 vaccines. Previously, the Chumakov Center has successfully developed two inactivated vaccines against tick-borne encephalitis and poliomyelitis produced using Vero cells [Here, we present the results of clinical trials of the tolerability, safety, and immunogenicity of the inactivated whole virion concentrated purified coronavirus vaccine CoviVac in adult volunteers aged 18–60 (phases I/II) and older (phase IIb). The primary outcomes for safety assessment were the frequency and severity of AEs within the observation period, and the primary immunogenicity endpoints were the geometric mean nAB titer (GMT) and seroconversion rate (defined as fourfold or higher increase in GMT of specific antibodies in the NT) following complete vaccination regimen in each cohort.