inclusion criteria: -aged 18 years or older on the day of inclusion. - -a female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies: is of non-childbearing potential. to be considered of non-childbearing potential, a female mut be post-menopausal for at least 1 year or surgically sterile. or is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to the first vaccination until at least 12 weeks after the last vaccination (ie, second dose of primary series or booster injection). a participant of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) within 4 hours before any dose of study intervention. - -informed consent form has been signed and dated. able to attend all scheduled visits and to comply with all study procedures. sars-cov-2 rapid serodiagnostic test performed at the time of enrollment to detect presence of sars-cov-2 antibodies (original phase 2 cohort). for persons living with human immunodeficiency virus (hiv), stable hiv infection determined by participant currently on antiretrovirals with cd4 count \> 200/mm3. does not intend to receive an authorized/approved covid-19 vaccine from first vaccination to 3 weeks after the second vaccination despite encouragement by the investigator to receive the authorized vaccine available to them at the time of enrollment. supplemental cohorts: for participants originally enrolled in the phase ii cohort of the study, informed consent has to be signed and dated for transitioning to supplemental cohort 2. supplemental cohorts, booster arms: received a complete primary vaccination series with an authorized/conditionally approved mrna covid-19 vaccine (mrna-1273 \[moderna\] or bnt162b2 \[pfizer/biontech\]) or adenovirus-vectored covid-19 vaccine (chadox1 ncov-19 \[oxford university/astrazeneca\] or ad26.cov2.s \[j\&j/janssen\]), with the last dose administered a minimum of 4 months prior to inclusion but not longer than 10 months prior to inclusion.

inclusion criteria: -aged 18 years or older on the day of inclusion. - -a female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies: is of non-childbearing potential. to be considered of non-childbearing potential, a female mut be post-menopausal for at least 1 year or surgically sterile. or is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to the first vaccination until at least 12 weeks after the last vaccination (ie, second dose of primary series or booster injection). a participant of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) within 4 hours before any dose of study intervention. - -informed consent form has been signed and dated. able to attend all scheduled visits and to comply with all study procedures. sars-cov-2 rapid serodiagnostic test performed at the time of enrollment to detect presence of sars-cov-2 antibodies (original phase 2 cohort). for persons living with human immunodeficiency virus (hiv), stable hiv infection determined by participant currently on antiretrovirals with cd4 count \> 200/mm3. does not intend to receive an authorized/approved covid-19 vaccine from first vaccination to 3 weeks after the second vaccination despite encouragement by the investigator to receive the authorized vaccine available to them at the time of enrollment. supplemental cohorts: for participants originally enrolled in the phase ii cohort of the study, informed consent has to be signed and dated for transitioning to supplemental cohort 2. supplemental cohorts, booster arms: received a complete primary vaccination series with an authorized/conditionally approved mrna covid-19 vaccine (mrna-1273 \[moderna\] or bnt162b2 \[pfizer/biontech\]) or adenovirus-vectored covid-19 vaccine (chadox1 ncov-19 \[oxford university/astrazeneca\] or ad26.cov2.s \[j\&j/janssen\]), with the last dose administered a minimum of 4 months prior to inclusion but not longer than 10 months prior to inclusion.

inclusion criteria: -aged 18 years or older on the day of inclusion. - -a female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies: is of non-childbearing potential. to be considered of non-childbearing potential, a female mut be post-menopausal for at least 1 year or surgically sterile. or is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to the first vaccination until at least 12 weeks after the last vaccination (ie, second dose of primary series or booster injection). a participant of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) within 4 hours before any dose of study intervention. - -informed consent form has been signed and dated. able to attend all scheduled visits and to comply with all study procedures. sars-cov-2 rapid serodiagnostic test performed at the time of enrollment to detect presence of sars-cov-2 antibodies (original phase 2 cohort). for persons living with human immunodeficiency virus (hiv), stable hiv infection determined by participant currently on antiretrovirals with cd4 count > 200/mm3. does not intend to receive an authorized/approved covid-19 vaccine from first vaccination to 3 weeks after the second vaccination despite encouragement by the investigator to receive the authorized vaccine available to them at the time of enrollment. supplemental cohorts: for participants originally enrolled in the phase ii cohort of the study, informed consent has to be signed and dated for transitioning to supplemental cohort 2. supplemental cohorts, booster arms: received a complete primary vaccination series with an authorized/conditionally approved mrna covid-19 vaccine (mrna-1273 [moderna] or bnt162b2 [pfizer/biontech]) or adenovirus-vectored covid-19 vaccine (chadox1 ncov-19 [oxford university/astrazeneca] or ad26.cov2.s [j&j/janssen]), with the last dose administered a minimum of 4 months prior to inclusion but not longer than 10 months prior to inclusion.

inclusion criteria: -aged 18 years or older on the day of inclusion. - -a female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies: is of non-childbearing potential. to be considered of non-childbearing potential, a female mut be post-menopausal for at least 1 year or surgically sterile. or is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to the first vaccination until at least 12 weeks after the last vaccination (ie, second dose of primary series or booster injection). a participant of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) within 4 hours before any dose of study intervention. - -informed consent form has been signed and dated. able to attend all scheduled visits and to comply with all study procedures. sars-cov-2 rapid serodiagnostic test performed at the time of enrollment to detect presence of sars-cov-2 antibodies (original phase 2 cohort). for persons living with human immunodeficiency virus (hiv), stable hiv infection determined by participant currently on antiretrovirals with cd4 count > 200/mm3. does not intend to receive an authorized/approved covid-19 vaccine from first vaccination to 3 weeks after the second vaccination despite encouragement by the investigator to receive the authorized vaccine available to them at the time of enrollment. supplemental cohorts: for participants originally enrolled in the phase ii cohort of the study, informed consent has to be signed and dated for transitioning to supplemental cohort 2. supplemental cohorts, booster arms: received a complete primary vaccination series with an authorized/conditionally approved mrna covid-19 vaccine (mrna-1273 [moderna] or bnt162b2 [pfizer/biontech]) or adenovirus-vectored covid-19 vaccine (chadox1 ncov-19 [oxford university/astrazeneca] or ad26.cov2.s [j&j/janssen]), with the last dose administered a minimum of 4 months prior to inclusion but not longer than 10 months prior to inclusion.

inclusion criteria: - aged 18 years or older on the day of inclusion. - a female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies: is of non-childbearing potential. to be considered of non-childbearing potential, a female mut be post-menopausal for at least 1 year or surgically sterile. or is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to the first vaccination until at least 12 weeks after the second vaccination. a participant of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) within 4 hours before any dose of study intervention. - informed consent form has been signed and dated. - able to attend all scheduled visits and to comply with all study procedures. - sars-cov-2 rapid serodiagnostic test performed at the time of enrollment to detect presence of sars-cov-2 antibodies (original phase 2 cohort). - for persons living with human immunodeficiency virus (hiv), stable hiv infection determined by participant currently on antiretrovirals with cd4 count > 200/mm3. - does not intend to receive an authorized/approved covid-19 vaccine from first vaccination to 3 weeks after the second vaccination despite encouragement by the investigator to receive the authorized vaccine available to them at the time of enrollment. - supplemental cohorts: for participants originally enrolled in the phase ii cohort of the study, informed consent has to be signed and dated for transitioning to supplemental cohort 2. - supplemental cohorts, booster arms: received a complete primary vaccination series with an authorized/conditionally approved mrna covid-19 vaccine (mrna-1273 [moderna] or bnt162b2 [pfizer/biontech]) or adenovirus-vectored covid-19 vaccine (chadox1 ncov-19 [oxford university/astrazeneca] or ad26.cov2.s [j&j/janssen]), with the last dose administered a minimum of 4 months prior to inclusion but not longer than 10 months prior to inclusion.

inclusion criteria: - aged 18 years or older on the day of inclusion. - a female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies: is of non-childbearing potential. to be considered of non-childbearing potential, a female mut be post-menopausal for at least 1 year or surgically sterile. or is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to the first vaccination until at least 12 weeks after the second vaccination. a participant of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) within 4 hours before any dose of study intervention. - informed consent form has been signed and dated. - able to attend all scheduled visits and to comply with all study procedures. - sars-cov-2 rapid serodiagnostic test performed at the time of enrollment to detect presence of sars-cov-2 antibodies (original phase 2 cohort). - for persons living with human immunodeficiency virus (hiv), stable hiv infection determined by participant currently on antiretrovirals with cd4 count > 200/mm3. - does not intend to receive an authorized/approved covid-19 vaccine from first vaccination to 3 weeks after the second vaccination despite encouragement by the investigator to receive the authorized vaccine available to them at the time of enrollment. - supplemental cohorts: for participants originally enrolled in the phase ii cohort of the study, informed consent has to be signed and dated for transitioning to supplemental cohort 2. - supplemental cohorts, booster arms: received a complete primary vaccination series with an authorized/conditionally approved mrna covid-19 vaccine (mrna-1273 [moderna] or bnt162b2 [pfizer/biontech]) or adenovirus-vectored covid-19 vaccine (chadox1 ncov-19 [oxford university/astrazeneca] or ad26.cov2.s [j&j/janssen]), with the last dose administered a minimum of 4 months prior to inclusion but not longer than 10 months prior to inclusion.

inclusion criteria : - aged 18 years or older on the day of inclusion. - a female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies: - is of non-childbearing potential. to be considered of non-childbearing potential, a female mut be post-menopausal for at least 1 year or surgically sterile. or - is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to the first vaccination until at least 12 weeks after the second vaccination. a subject of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) within 4 hours before any dose of study intervention. - informed consent form has been signed and dated. - able to attend all scheduled visits and to comply with all trial procedures. - sars-cov-2 rapid serodiagnostic test performed at the time of enrollment to detect presence of sars-cov-2 antibodies. - for persons living with human immunodeficiency virus (hiv), stable hiv infection determined by participant currently on antiretrovirals with cd4 count > 200/mm3. - does not intend to receive an authorized/approved covid-19 vaccine from first vaccination to 3 weeks after the second vaccination despite encouragement by the investigator to receive the authorized vaccine available to them at the time of enrollment

inclusion criteria : - aged 18 years or older on the day of inclusion. - a female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies: - is of non-childbearing potential. to be considered of non-childbearing potential, a female mut be post-menopausal for at least 1 year or surgically sterile. or - is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to the first vaccination until at least 12 weeks after the second vaccination. a subject of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) within 4 hours before any dose of study intervention. - informed consent form has been signed and dated. - able to attend all scheduled visits and to comply with all trial procedures. - sars-cov-2 rapid serodiagnostic test performed at the time of enrollment to detect presence of sars-cov-2 antibodies. - for persons living with human immunodeficiency virus (hiv), stable hiv infection determined by participant currently on antiretrovirals with cd4 count > 200/mm3. - does not intend to receive an authorized/approved covid-19 vaccine from first vaccination to 3 weeks after the second vaccination despite encouragement by the investigator to receive the authorized vaccine available to them at the time of enrollment