inclusion criteria: * people aged 21 to 65 years old, with body weight ≥ 50 kg for males and ≥ 45 kg for females, body mass index (bmi) within the range of 19.0-30.0 (including the boundary value), who can provide legal identification; * subjects who agree to participate in this study voluntarily and sign an informed consent form. * subject who has the ability to understand the study procedures and be able to attend all scheduled follow-up; * individuals who completed basic vaccination of licensed vaccine or further received the first booster dose vaccination 4\~12 months prior to recruitment in this study（including but not limited to mrna or non-mrna vaccine）. * female subjects who are not pregnant or breast-feeding; * women of childbearing age who agree to use effective contraception during the study; or have been using effective contraception within 2 weeks prior to enrollment.

inclusion criteria: * people aged 21 to 65 years old, with body weight ≥ 50 kg for males and ≥ 45 kg for females, body mass index (bmi) within the range of 19.0-30.0 (including the boundary value), who can provide legal identification; * subjects who agree to participate in this study voluntarily and sign an informed consent form. * subject who has the ability to understand the study procedures and be able to attend all scheduled follow-up; * individuals who completed basic vaccination of licensed vaccine or further received the first booster dose vaccination 4\~12 months prior to recruitment in this study（including but not limited to mrna or non-mrna vaccine）. * female subjects who are not pregnant or breast-feeding; * women of childbearing age who agree to use effective contraception during the study; or have been using effective contraception within 2 weeks prior to enrollment.

inclusion criteria: people aged 21 to 65 years old, with body weight ≥ 50 kg for males and ≥ 45 kg for females, body mass index (bmi) within the range of 19.0-30.0 (including the boundary value), who can provide legal identification; subjects who agree to participate in this study voluntarily and sign an informed consent form. subject who has the ability to understand the study procedures and be able to attend all scheduled follow-up; individuals who completed basic vaccination of licensed vaccine or further received the first booster dose vaccination 4~12 months prior to recruitment in this study（including but not limited to mrna or non-mrna vaccine）. female subjects who are not pregnant or breast-feeding; women of childbearing age who agree to use effective contraception during the study; or have been using effective contraception within 2 weeks prior to enrollment.

inclusion criteria: people aged 21 to 65 years old, with body weight ≥ 50 kg for males and ≥ 45 kg for females, body mass index (bmi) within the range of 19.0-30.0 (including the boundary value), who can provide legal identification; subjects who agree to participate in this study voluntarily and sign an informed consent form. subject who has the ability to understand the study procedures and be able to attend all scheduled follow-up; individuals who completed basic vaccination of licensed vaccine or further received the first booster dose vaccination 4~12 months prior to recruitment in this study（including but not limited to mrna or non-mrna vaccine）. female subjects who are not pregnant or breast-feeding; women of childbearing age who agree to use effective contraception during the study; or have been using effective contraception within 2 weeks prior to enrollment.