inclusion criteria: * adult volunteers aged 18 years and above who have received 1 dose of intramuscular ad5-ncov \> 56 days at the enrollment. * volunteers who have provided informed consent and signed the informed consent form. * volunteers who are able and willing to comply with the requirements of the clinical study protocol, and can complete the entire follow-up period of this study.

inclusion criteria: * adult volunteers aged 18 years and above who have received 1 dose of intramuscular ad5-ncov \> 56 days at the enrollment. * volunteers who have provided informed consent and signed the informed consent form. * volunteers who are able and willing to comply with the requirements of the clinical study protocol, and can complete the entire follow-up period of this study.

inclusion criteria: adult volunteers aged 18 years and above who have received 1 dose of intramuscular ad5-ncov > 56 days at the enrollment. subjects who have provided informed consent and signed the informed consent form. subjects who are able and willing to comply with the requirements of the clinical study protocol, and can complete the entire follow-up period of this study.

inclusion criteria: adult volunteers aged 18 years and above who have received 1 dose of intramuscular ad5-ncov > 56 days at the enrollment. subjects who have provided informed consent and signed the informed consent form. subjects who are able and willing to comply with the requirements of the clinical study protocol, and can complete the entire follow-up period of this study.