inclusion criteria: * participant must be 18 years of age and older, at the time of signing the informed consent; * participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, clinical laboratory tests, and medical judgement of the investigator; * participants who are able to attend all scheduled visits and comply with all study procedures; * female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the 1st study vaccination to 12 weeks after the last study vaccination; * female participants with a negative urine or serum pregnancy test at screening; * capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in protocol; \<stage2\> * participants who have received 2 doses of gbp510 25μg adjuvanted with as03 or chadox1-s and have blood samples until visit 7 in stage 1 * participants who received a primary series of gbp510 or chadox1-s at least 12 weeks prior to booster vaccination in stage 2 * participants who are able to attend all additionally scheduled visits and comply with all study procedures. * female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the booster dose (3rd study vaccination) to 12 weeks after the booster dose * female participants with a negative urine or serum pregnancy test prior to the booster dose (the third dose of study vaccine) * capable of giving an informed consent for stage 2 study in compliance with the requirements and restrictions listed in the informed consent form (icf) for stage 2 and in this protocol.

inclusion criteria: * participant must be 18 years of age and older, at the time of signing the informed consent; * participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, clinical laboratory tests, and medical judgement of the investigator; * participants who are able to attend all scheduled visits and comply with all study procedures; * female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the 1st study vaccination to 12 weeks after the last study vaccination; * female participants with a negative urine or serum pregnancy test at screening; * capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in protocol; \<stage2\> * participants who have received 2 doses of gbp510 25μg adjuvanted with as03 or chadox1-s and have blood samples until visit 7 in stage 1 * participants who received a primary series of gbp510 or chadox1-s at least 12 weeks prior to booster vaccination in stage 2 * participants who are able to attend all additionally scheduled visits and comply with all study procedures. * female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the booster dose (3rd study vaccination) to 12 weeks after the booster dose * female participants with a negative urine or serum pregnancy test prior to the booster dose (the third dose of study vaccine) * capable of giving an informed consent for stage 2 study in compliance with the requirements and restrictions listed in the informed consent form (icf) for stage 2 and in this protocol.

inclusion criteria: participant must be 18 years of age and older, at the time of signing the informed consent; participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, clinical laboratory tests, and medical judgement of the investigator; participants who are able to attend all scheduled visits and comply with all study procedures; female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the 1st study vaccination to 12 weeks after the last study vaccination; female participants with a negative urine or serum pregnancy test at screening; capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in protocol; <stage2> participants who have received 2 doses of gbp510 25μg adjuvanted with as03 or chadox1-s and have blood samples until visit 7 in stage 1 participants who received a primary series of gbp510 or chadox1-s at least 12 weeks prior to booster vaccination in stage 2 participants who are able to attend all additionally scheduled visits and comply with all study procedures. female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the booster dose (3rd study vaccination) to 12 weeks after the booster dose female participants with a negative urine or serum pregnancy test prior to the booster dose (the third dose of study vaccine) capable of giving an informed consent for stage 2 study in compliance with the requirements and restrictions listed in the informed consent form (icf) for stage 2 and in this protocol.

inclusion criteria: participant must be 18 years of age and older, at the time of signing the informed consent; participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, clinical laboratory tests, and medical judgement of the investigator; participants who are able to attend all scheduled visits and comply with all study procedures; female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the 1st study vaccination to 12 weeks after the last study vaccination; female participants with a negative urine or serum pregnancy test at screening; capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in protocol; <stage2> participants who have received 2 doses of gbp510 25μg adjuvanted with as03 or chadox1-s and have blood samples until visit 7 in stage 1 participants who received a primary series of gbp510 or chadox1-s at least 12 weeks prior to booster vaccination in stage 2 participants who are able to attend all additionally scheduled visits and comply with all study procedures. female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the booster dose (3rd study vaccination) to 12 weeks after the booster dose female participants with a negative urine or serum pregnancy test prior to the booster dose (the third dose of study vaccine) capable of giving an informed consent for stage 2 study in compliance with the requirements and restrictions listed in the informed consent form (icf) for stage 2 and in this protocol.

inclusion criteria: - participant must be 18 years of age and older, at the time of signing the informed consent; - participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, clinical laboratory tests, and medical judgement of the investigator; - participants who are able to attend all scheduled visits and comply with all study procedures; - female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the 1st study vaccination to 12 weeks after the last study vaccination; - female participants with a negative urine or serum pregnancy test at screening; - capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in protocol;

inclusion criteria: - participant must be 18 years of age and older, at the time of signing the informed consent; - participants who are healthy or medically stable as determined by medical evaluation including medical history, physical examination, clinical laboratory tests, and medical judgement of the investigator; - participants who are able to attend all scheduled visits and comply with all study procedures; - female participants of childbearing potential must agree to be heterosexually inactive, or agree to consistently use at least one acceptable method of contraception from at least 4 weeks prior to the 1st study vaccination to 12 weeks after the last study vaccination; - female participants with a negative urine or serum pregnancy test at screening; - capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in protocol;