two dose level of Recombinant COVID-19 variant vaccine (Sf9 cell) compete with Recombinant COVID-19 vaccine (CHO cell) and Recombinant COVID-19 vaccine (Sf9 cell) .
A single-center, randomized, double-blind, controlled clinical trial to evaluate the safety and immunogenicity of booster vaccination of Recombinant COVID-19 variant vaccine (Sf9 cell) in healthy people aged 18 years and older after completing 2 or 3 doses of novel coronavirus inactivated vaccine (Vero cells)