inclusion criteria: * age eligible for observation in this clinical trial: adults aged 18 years and above * subjects voluntarily participate in this study, sign informed consent, provide legal identification, and understand and comply with the requirements of the test protocol * more than 4 months after the completion of the whole course of recombinant novel coronavirus protein vaccine (cho cell) basic immunization or more than 4 months after the completion of the novel coronavirus mrna vaccine basic immunization * female and male participants of childbearing age took effective contraception during the study period

inclusion criteria: * age eligible for observation in this clinical trial: adults aged 18 years and above * subjects voluntarily participate in this study, sign informed consent, provide legal identification, and understand and comply with the requirements of the test protocol * more than 4 months after the completion of the whole course of recombinant novel coronavirus protein vaccine (cho cell) basic immunization or more than 4 months after the completion of the novel coronavirus mrna vaccine basic immunization * female and male participants of childbearing age took effective contraception during the study period

inclusion criteria: age eligible for observation in this clinical trial: adults aged 18 years and above subjects voluntarily participate in this study, sign informed consent, provide legal identification, and understand and comply with the requirements of the test protocol more than 4 months after the completion of the whole course of recombinant novel coronavirus protein vaccine (cho cell) basic immunization or more than 4 months after the completion of the novel coronavirus mrna vaccine basic immunization female and male participants of childbearing age took effective contraception during the study period

inclusion criteria: age eligible for observation in this clinical trial: adults aged 18 years and above subjects voluntarily participate in this study, sign informed consent, provide legal identification, and understand and comply with the requirements of the test protocol more than 4 months after the completion of the whole course of recombinant novel coronavirus protein vaccine (cho cell) basic immunization or more than 4 months after the completion of the novel coronavirus mrna vaccine basic immunization female and male participants of childbearing age took effective contraception during the study period