This Phase 3 trial is a Randomized, observer-blind, placebo-controlled two arms parallel-group, prospective intervention study

Approximately 1620 subjects aged 18-59 years will be enrolled in this trial for efficacy evaluation.

Subjects will be divided into 2 treatment arms that are the vaccinated group and the placebo group with ratio 1:1.

The vaccinated arms will be grouped into three different lot numbers (lot 1/lot 2/ lot 3) of the SARS-CoV-2 vaccine.