inclusion criteria: - a covid-19 vaccine is planned. - older adults subjects aged 60-80 years or young adults subjects aged 18-59 years. - able and willing to follow the requirements of the clinical trial protocol and complete the study follow-up for 12 months. - hbsag, anti-hcv, hiv and tpha were negative. - body temperature ≤37.0℃.

inclusion criteria: - a covid-19 vaccine is planned. - older adults subjects aged 60-80 years or young adults subjects aged 18-59 years. - able and willing to follow the requirements of the clinical trial protocol and complete the study follow-up for 12 months. - hbsag, anti-hcv, hiv and tpha were negative. - body temperature ≤37.0℃.