inclusion criteria: 1. male and female participants 18-65 years of age at the time of signing the informed consent form for the study. 2. good general health as confirmed by assessments completed no more than 30 days before study d0. participants with mild to moderate well controlled comorbidities or having a medically stable condition, will be eligible. a stable medical condition is defined as disease not requiring significant change in therapy or hospitalization due to worsening during the 3 months prior to enrollment, and according to the judgment of the investigator, hospitalization during the entire study period is not anticipated. 3. have received a minimum of 2 doses of an authorized covid-19 vaccine at least 4 months prior to the investigational booster dose injection. proof of vaccination can be provided as a digital copy of the vaccination receipt on the participant's device, a screenshot of the receipt on the device, or a printed paper copy. 4. male participants, and heterosexually active females of child-bearing potential, must practice adequate contraception for 30 days prior to the injection and must agree to continue adequate contraception until 180 days after the injection. negative pregnancy test will be obtained from female participants of child-bearing potential at screening and at day 0. 5. provide a written informed consent for the study prior to performing any study-related procedure. the investigator or a qualified designee must ensure the appropriate consent is in place.

inclusion criteria: 1. male and female participants 18-65 years of age at the time of signing the informed consent form for the study. 2. good general health as confirmed by assessments completed no more than 30 days before study d0. participants with mild to moderate well controlled comorbidities or having a medically stable condition, will be eligible. a stable medical condition is defined as disease not requiring significant change in therapy or hospitalization due to worsening during the 3 months prior to enrollment, and according to the judgment of the investigator, hospitalization during the entire study period is not anticipated. 3. have received a minimum of 2 doses of an authorized covid-19 vaccine at least 4 months prior to the investigational booster dose injection. proof of vaccination can be provided as a digital copy of the vaccination receipt on the participant's device, a screenshot of the receipt on the device, or a printed paper copy. 4. male participants, and heterosexually active females of child-bearing potential, must practice adequate contraception for 30 days prior to the injection and must agree to continue adequate contraception until 180 days after the injection. negative pregnancy test will be obtained from female participants of child-bearing potential at screening and at day 0. 5. provide a written informed consent for the study prior to performing any study-related procedure. the investigator or a qualified designee must ensure the appropriate consent is in place.

inclusion criteria: male and female participants 18-65 years of age at the time of signing the informed consent form for the study. good general health as confirmed by assessments completed no more than 30 days before study d0. participants with mild to moderate well controlled comorbidities or having a medically stable condition, will be eligible. a stable medical condition is defined as disease not requiring significant change in therapy or hospitalization due to worsening during the 3 months prior to enrollment, and according to the judgment of the investigator, hospitalization during the entire study period is not anticipated. have received a minimum of 2 doses of an authorized covid-19 vaccine at least 4 months prior to the investigational booster dose injection. proof of vaccination can be provided as a digital copy of the vaccination receipt on the participant's device, a screenshot of the receipt on the device, or a printed paper copy. male participants, and heterosexually active females of child-bearing potential, must practice adequate contraception for 30 days prior to the injection and must agree to continue adequate contraception until 180 days after the injection. negative pregnancy test will be obtained from female participants of child-bearing potential at screening and at day 0. provide a written informed consent for the study prior to performing any study-related procedure. the investigator or a qualified designee must ensure the appropriate consent is in place.

inclusion criteria: male and female participants 18-65 years of age at the time of signing the informed consent form for the study. good general health as confirmed by assessments completed no more than 30 days before study d0. participants with mild to moderate well controlled comorbidities or having a medically stable condition, will be eligible. a stable medical condition is defined as disease not requiring significant change in therapy or hospitalization due to worsening during the 3 months prior to enrollment, and according to the judgment of the investigator, hospitalization during the entire study period is not anticipated. have received a minimum of 2 doses of an authorized covid-19 vaccine at least 4 months prior to the investigational booster dose injection. proof of vaccination can be provided as a digital copy of the vaccination receipt on the participant's device, a screenshot of the receipt on the device, or a printed paper copy. male participants, and heterosexually active females of child-bearing potential, must practice adequate contraception for 30 days prior to the injection and must agree to continue adequate contraception until 180 days after the injection. negative pregnancy test will be obtained from female participants of child-bearing potential at screening and at day 0. provide a written informed consent for the study prior to performing any study-related procedure. the investigator or a qualified designee must ensure the appropriate consent is in place.