The Phase II clinical trial in China is a randomized, double-blind, placebo-controlled, dose-exploring clinical trial that aims to evaluate the safety and safety of pGX9501 at different dose levels through ID and subsequent EP administration using CELLECTRA® 2000 equipment. Immunogenicity, the subjects are healthy adults and elderly volunteers. The trial will start in December 2020. As of the latest practicable date, we have completed the administration of all planned subjects and the 30-day follow-up after the second dose of vaccination, except for those who voluntarily withdrew due to unrelated serious adverse events or personal reasons.