inclusion criteria: - signed informed consent form - ability to comply with the study procedures based on the investigator's assessment - males and females aged 18-60 years, inclusive, at the date of consent. - negative pregnancy test (for females of childbearing potential) - patients of childbearing potential and their partners with preserved reproductive function must agree to use reliable contraceptive methods starting from the time of informed consent for 3 months after visit 1. this requirement does not apply to patients and their partners who underwent surgical sterilization. reliable contraceptive methods include one barrier method in combination with one of the following: spermicides, intrauterine device/oral contraceptives. - cohort 1 only. negative test for sars-cov-2 igm and igg at screening - cohort 2 only. negative test for sars-cov-2 igm at screening - cohort 2 only. confirmed by sars-cov-2 rna test, history of covid-19 with documented recovery at least 4 month prior consent date.

inclusion criteria: - signed informed consent form - ability to comply with the study procedures based on the investigator's assessment - males and females aged 18-60 years, inclusive, at the date of consent. - negative pregnancy test (for females of childbearing potential) - patients of childbearing potential and their partners with preserved reproductive function must agree to use reliable contraceptive methods starting from the time of informed consent for 3 months after visit 1. this requirement does not apply to patients and their partners who underwent surgical sterilization. reliable contraceptive methods include one barrier method in combination with one of the following: spermicides, intrauterine device/oral contraceptives. - cohort 1 only. negative test for sars-cov-2 igm and igg at screening - cohort 2 only. negative test for sars-cov-2 igm at screening - cohort 2 only. confirmed by sars-cov-2 rna test, history of covid-19 with documented recovery at least 4 month prior consent date.