A study of the safety and immunogenicity of a new vaccine for the prevention of COVID-19 based on virus-like particles in phase I clinical trials

Introduction. One of the more promising developments in preventing the spread of infections, including COVID-19, is the production of vaccines based on virus-like particles (VLP). Currently, in the National Research Center for Epidemiology and Microbiology named after N.F. Gamaleya of the Ministry of Health of the Russia has developed a VLP-based vaccine against COVID-19. The aim of this study is to evaluate the tolerability, safety and immunogenicity of a new vaccine for the prevention of COVID–19 based on VLP compared with placebo for 21 days after two intramuscular injections in phase I clinical trials. Materials and methods. A double-blind, placebo-controlled study of the tolerability, safety and immunogenicity of a vaccine for the prevention of COVID-19 based on VLP was conducted with a dose of the drug containing 40 and 80 micrograms of antigen, the placebo being 0.9% NaCl. The presence or absence of adverse events (AEs) after vaccination was noted in 180 volunteers aged 18 to 55 years; clinical and biochemical blood parameters, the intensity of humoral and cellular immunity before and after vaccination were assessed using enzyme immunoassay, neutralization reactions, lymphocyte blast transformation reactions and flow cytometry. Results. An analysis of the tolerability and safety of the new COVID-19 VLP-vaccine showed that most adverse events were registered within the first 10 days after vaccination, mainly after the first vaccination. In the period from 11 to 21 days after vaccination, AEs were observed in isolated cases. No deaths, serious or other AEs have been reported. The administration of the studied vaccine to the volunteers had no negative effect on the basic vital signs. A comparative analysis of immunogenicity indicators in volunteers showed that the administration of a vaccine with both an antigen content of 40 µg and an antigen content of 80 µg leads to a pronounced and significant increase in the level of specific immunoglobulins, virus neutralizing antibodies and activation of a cell-mediated immune response. As part of the phase I clinical trials, a dose of 80 µg was selected as optimal. Conclusion. It has been shown that a new vaccine for the prevention of COVID-19 based on VLP with an antigen content of 40 and 80 µg when administered intramuscularly to volunteers does not cause serious adverse events and induces a tense humoral and cellular immune response.