inclusion criteria: subjects are eligible to be included in the study only if all of the following criteria apply at any time starting from screening up to day 1 prior to ip administration: 1. capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol. 2. male or female subjects who are ≥18 years old at the time of screening (signing the icf): 1. for the younger adult group: 18 to 55 years, inclusive 2. for the older adult group: ≥56 to \<80 years 3. have a body mass index (bmi) between 18.5 and 35.0 kg/m2. 4. subjects who are of general good health according to the investigator's assessment, based on a complete medical history without major pathology, and as determined by medical evaluation (including physical examination, electrocardiogram (ecg), vital signs, and clinical laboratory tests). subjects in the older adult population who have medically stable, well-controlled comorbidities may be enrolled at the discretion of the investigator. note: all clinical laboratory values should be within reference ranges unless confirmed by investigator or delegate as not clinically significant. one repeat evaluation of ecg, vital signs, and clinical laboratory tests will be permitted, at the discretion of the investigator. 5. subjects who test negative for hepatitis b surface antigen (hbsag), hepatitis b core antibodies (anti-hbc), anti-hepatitis c virus (hcv) antibodies, and anti-human immunodeficiency virus (hiv) 1 and 2 antibodies at screening. 6. subjects who test negative for sars-cov-2 infection, based on a reverse transcriptase polymerase chain reaction (rt-pcr) test and serological test for sars-cov-2 igm and/or igg antibodies at screening. 7. female subjects are eligible to participate if not pregnant, not breastfeeding, and at least 1 of the following conditions applies: 1. is not a woman of childbearing potential (wocbp), defined as: surgically sterile (documented hysterectomy, bilateral salpingectomy, or bilateral oophorectomy, as confirmed by review of the subject's medical records, medical examination, or medical history interview), or postmenopausal (defined as no menses for 12 months without an alternative medical cause. a high follicle-stimulating hormone \[fsh\] level in the postmenopausal range may be used to confirm a postmenopausal state in women not using hormonal contraception or hormonal replacement therapy \[hrt\]. however, in the absence of 12 months of amenorrhea, a single fsh measurement is insufficient). female subjects on hrt and whose menopausal status is in doubt will be required to use 1 of the non estrogen hormonal highly effective contraception methods from day 1 until at least 6 months after the second dose of ip if they wish to continue their hrt during the study. otherwise, they must discontinue hrt to allow confirmation of postmenopausal status before study enrollment. 2. is a wocbp who agrees to use a highly effective method of contraception consistently and correctly from day 1 until at least 6 months after the second dose of ip. 8. nonsterilized male subjects with female partners of childbearing potential are eligible to participate if they agree to one of the following from day 1 until at least 6 months after the second dose of ip and refrain from donating sperm during this period: 1. are abstinent from penile-vaginal intercourse as their usual and preferred lifestyle (abstinent on a long-term and persistent basis) and agree to remain abstinent. 2. agree to use a male condom and have their partner use of a contraceptive method with a failure rate of \<1% per year when having penile-vaginal intercourse with a wocbp who is not currently pregnant. 3. male subjects with a pregnant or breastfeeding partner must agree to remain abstinent from penile-vaginal intercourse or use a male condom during each episode of penile penetration.

inclusion criteria: subjects are eligible to be included in the study only if all of the following criteria apply at any time starting from screening up to day 1 prior to ip administration: 1. capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol. 2. male or female subjects who are ≥18 years old at the time of screening (signing the icf): 1. for the younger adult group: 18 to 55 years, inclusive 2. for the older adult group: ≥56 to \<80 years 3. have a body mass index (bmi) between 18.5 and 35.0 kg/m2. 4. subjects who are of general good health according to the investigator's assessment, based on a complete medical history without major pathology, and as determined by medical evaluation (including physical examination, electrocardiogram (ecg), vital signs, and clinical laboratory tests). subjects in the older adult population who have medically stable, well-controlled comorbidities may be enrolled at the discretion of the investigator. note: all clinical laboratory values should be within reference ranges unless confirmed by investigator or delegate as not clinically significant. one repeat evaluation of ecg, vital signs, and clinical laboratory tests will be permitted, at the discretion of the investigator. 5. subjects who test negative for hepatitis b surface antigen (hbsag), hepatitis b core antibodies (anti-hbc), anti-hepatitis c virus (hcv) antibodies, and anti-human immunodeficiency virus (hiv) 1 and 2 antibodies at screening. 6. subjects who test negative for sars-cov-2 infection, based on a reverse transcriptase polymerase chain reaction (rt-pcr) test and serological test for sars-cov-2 igm and/or igg antibodies at screening. 7. female subjects are eligible to participate if not pregnant, not breastfeeding, and at least 1 of the following conditions applies: 1. is not a woman of childbearing potential (wocbp), defined as: surgically sterile (documented hysterectomy, bilateral salpingectomy, or bilateral oophorectomy, as confirmed by review of the subject's medical records, medical examination, or medical history interview), or postmenopausal (defined as no menses for 12 months without an alternative medical cause. a high follicle-stimulating hormone \[fsh\] level in the postmenopausal range may be used to confirm a postmenopausal state in women not using hormonal contraception or hormonal replacement therapy \[hrt\]. however, in the absence of 12 months of amenorrhea, a single fsh measurement is insufficient). female subjects on hrt and whose menopausal status is in doubt will be required to use 1 of the non estrogen hormonal highly effective contraception methods from day 1 until at least 6 months after the second dose of ip if they wish to continue their hrt during the study. otherwise, they must discontinue hrt to allow confirmation of postmenopausal status before study enrollment. 2. is a wocbp who agrees to use a highly effective method of contraception consistently and correctly from day 1 until at least 6 months after the second dose of ip. 8. nonsterilized male subjects with female partners of childbearing potential are eligible to participate if they agree to one of the following from day 1 until at least 6 months after the second dose of ip and refrain from donating sperm during this period: 1. are abstinent from penile-vaginal intercourse as their usual and preferred lifestyle (abstinent on a long-term and persistent basis) and agree to remain abstinent. 2. agree to use a male condom and have their partner use of a contraceptive method with a failure rate of \<1% per year when having penile-vaginal intercourse with a wocbp who is not currently pregnant. 3. male subjects with a pregnant or breastfeeding partner must agree to remain abstinent from penile-vaginal intercourse or use a male condom during each episode of penile penetration.

inclusion criteria: subjects are eligible to be included in the study only if all of the following criteria apply at any time starting from screening up to day 1 prior to ip administration: capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol. male or female subjects who are ≥18 years old at the time of screening (signing the icf): for the younger adult group: 18 to 55 years, inclusive for the older adult group: ≥56 to <80 years have a body mass index (bmi) between 18.5 and 35.0 kg/m2. subjects who are of general good health according to the investigator's assessment, based on a complete medical history without major pathology, and as determined by medical evaluation (including physical examination, electrocardiogram (ecg), vital signs, and clinical laboratory tests). subjects in the older adult population who have medically stable, well-controlled comorbidities may be enrolled at the discretion of the investigator. note: all clinical laboratory values should be within reference ranges unless confirmed by investigator or delegate as not clinically significant. one repeat evaluation of ecg, vital signs, and clinical laboratory tests will be permitted, at the discretion of the investigator. subjects who test negative for hepatitis b surface antigen (hbsag), hepatitis b core antibodies (anti-hbc), anti-hepatitis c virus (hcv) antibodies, and anti-human immunodeficiency virus (hiv) 1 and 2 antibodies at screening. subjects who test negative for sars-cov-2 infection, based on a reverse transcriptase polymerase chain reaction (rt-pcr) test and serological test for sars-cov-2 igm and/or igg antibodies at screening. female subjects are eligible to participate if not pregnant, not breastfeeding, and at least 1 of the following conditions applies: is not a woman of childbearing potential (wocbp), defined as: surgically sterile (documented hysterectomy, bilateral salpingectomy, or bilateral oophorectomy, as confirmed by review of the subject's medical records, medical examination, or medical history interview), or postmenopausal (defined as no menses for 12 months without an alternative medical cause. a high follicle-stimulating hormone [fsh] level in the postmenopausal range may be used to confirm a postmenopausal state in women not using hormonal contraception or hormonal replacement therapy [hrt]. however, in the absence of 12 months of amenorrhea, a single fsh measurement is insufficient). female subjects on hrt and whose menopausal status is in doubt will be required to use 1 of the non estrogen hormonal highly effective contraception methods from day 1 until at least 6 months after the second dose of ip if they wish to continue their hrt during the study. otherwise, they must discontinue hrt to allow confirmation of postmenopausal status before study enrollment. is a wocbp who agrees to use a highly effective method of contraception consistently and correctly from day 1 until at least 6 months after the second dose of ip. nonsterilized male subjects with female partners of childbearing potential are eligible to participate if they agree to one of the following from day 1 until at least 6 months after the second dose of ip and refrain from donating sperm during this period: are abstinent from penile-vaginal intercourse as their usual and preferred lifestyle (abstinent on a long-term and persistent basis) and agree to remain abstinent. agree to use a male condom and have their partner use of a contraceptive method with a failure rate of <1% per year when having penile-vaginal intercourse with a wocbp who is not currently pregnant. male subjects with a pregnant or breastfeeding partner must agree to remain abstinent from penile-vaginal intercourse or use a male condom during each episode of penile penetration.

inclusion criteria: subjects are eligible to be included in the study only if all of the following criteria apply at any time starting from screening up to day 1 prior to ip administration: capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol. male or female subjects who are ≥18 years old at the time of screening (signing the icf): for the younger adult group: 18 to 55 years, inclusive for the older adult group: ≥56 to <80 years have a body mass index (bmi) between 18.5 and 35.0 kg/m2. subjects who are of general good health according to the investigator's assessment, based on a complete medical history without major pathology, and as determined by medical evaluation (including physical examination, electrocardiogram (ecg), vital signs, and clinical laboratory tests). subjects in the older adult population who have medically stable, well-controlled comorbidities may be enrolled at the discretion of the investigator. note: all clinical laboratory values should be within reference ranges unless confirmed by investigator or delegate as not clinically significant. one repeat evaluation of ecg, vital signs, and clinical laboratory tests will be permitted, at the discretion of the investigator. subjects who test negative for hepatitis b surface antigen (hbsag), hepatitis b core antibodies (anti-hbc), anti-hepatitis c virus (hcv) antibodies, and anti-human immunodeficiency virus (hiv) 1 and 2 antibodies at screening. subjects who test negative for sars-cov-2 infection, based on a reverse transcriptase polymerase chain reaction (rt-pcr) test and serological test for sars-cov-2 igm and/or igg antibodies at screening. female subjects are eligible to participate if not pregnant, not breastfeeding, and at least 1 of the following conditions applies: is not a woman of childbearing potential (wocbp), defined as: surgically sterile (documented hysterectomy, bilateral salpingectomy, or bilateral oophorectomy, as confirmed by review of the subject's medical records, medical examination, or medical history interview), or postmenopausal (defined as no menses for 12 months without an alternative medical cause. a high follicle-stimulating hormone [fsh] level in the postmenopausal range may be used to confirm a postmenopausal state in women not using hormonal contraception or hormonal replacement therapy [hrt]. however, in the absence of 12 months of amenorrhea, a single fsh measurement is insufficient). female subjects on hrt and whose menopausal status is in doubt will be required to use 1 of the non estrogen hormonal highly effective contraception methods from day 1 until at least 6 months after the second dose of ip if they wish to continue their hrt during the study. otherwise, they must discontinue hrt to allow confirmation of postmenopausal status before study enrollment. is a wocbp who agrees to use a highly effective method of contraception consistently and correctly from day 1 until at least 6 months after the second dose of ip. nonsterilized male subjects with female partners of childbearing potential are eligible to participate if they agree to one of the following from day 1 until at least 6 months after the second dose of ip and refrain from donating sperm during this period: are abstinent from penile-vaginal intercourse as their usual and preferred lifestyle (abstinent on a long-term and persistent basis) and agree to remain abstinent. agree to use a male condom and have their partner use of a contraceptive method with a failure rate of <1% per year when having penile-vaginal intercourse with a wocbp who is not currently pregnant. male subjects with a pregnant or breastfeeding partner must agree to remain abstinent from penile-vaginal intercourse or use a male condom during each episode of penile penetration.

inclusion criteria: subjects are eligible to be included in the study only if all of the following criteria apply at any time starting from screening up to day 1 prior to ip administration: 1. capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol. 2. male or female subjects who are ≥18 years old at the time of screening (signing the icf): 1. for the younger adult group: 18 to 55 years, inclusive 2. for the older adult group: ≥56 to <80 years 3. have a body mass index (bmi) between 18.5 and 35.0 kg/m2. 4. subjects who are of general good health according to the investigator's assessment, based on a complete medical history without major pathology, and as determined by medical evaluation (including physical examination, electrocardiogram (ecg), vital signs, and clinical laboratory tests). subjects in the older adult population who have medically stable, well-controlled comorbidities may be enrolled at the discretion of the investigator. note: all clinical laboratory values should be within reference ranges unless confirmed by investigator or delegate as not clinically significant. one repeat evaluation of ecg, vital signs, and clinical laboratory tests will be permitted, at the discretion of the investigator. 5. subjects who test negative for hepatitis b surface antigen (hbsag), hepatitis b core antibodies (anti-hbc), anti-hepatitis c virus (hcv) antibodies, and anti-human immunodeficiency virus (hiv) 1 and 2 antibodies at screening. 6. subjects who test negative for sars-cov-2 infection, based on a reverse transcriptase polymerase chain reaction (rt-pcr) test and serological test for sars-cov-2 igm and/or igg antibodies at screening. 7. female subjects are eligible to participate if not pregnant, not breastfeeding, and at least 1 of the following conditions applies: 1. is not a woman of childbearing potential (wocbp), defined as: surgically sterile (documented hysterectomy, bilateral salpingectomy, or bilateral oophorectomy, as confirmed by review of the subject's medical records, medical examination, or medical history interview), or postmenopausal (defined as no menses for 12 months without an alternative medical cause. a high follicle-stimulating hormone [fsh] level in the postmenopausal range may be used to confirm a postmenopausal state in women not using hormonal contraception or hormonal replacement therapy [hrt]. however, in the absence of 12 months of amenorrhea, a single fsh measurement is insufficient). female subjects on hrt and whose menopausal status is in doubt will be required to use 1 of the non estrogen hormonal highly effective contraception methods from day 1 until at least 6 months after the second dose of ip if they wish to continue their hrt during the study. otherwise, they must discontinue hrt to allow confirmation of postmenopausal status before study enrollment. 2. is a wocbp who agrees to use a highly effective method of contraception consistently and correctly from day 1 until at least 6 months after the second dose of ip. 8. nonsterilized male subjects with female partners of childbearing potential are eligible to participate if they agree to one of the following from day 1 until at least 6 months after the second dose of ip and refrain from donating sperm during this period: 1. are abstinent from penile-vaginal intercourse as their usual and preferred lifestyle (abstinent on a long-term and persistent basis) and agree to remain abstinent. 2. agree to use a male condom and have their partner use of a contraceptive method with a failure rate of <1% per year when having penile-vaginal intercourse with a wocbp who is not currently pregnant. 3. male subjects with a pregnant or breastfeeding partner must agree to remain abstinent from penile-vaginal intercourse or use a male condom during each episode of penile penetration.

inclusion criteria: subjects are eligible to be included in the study only if all of the following criteria apply at any time starting from screening up to day 1 prior to ip administration: 1. capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (icf) and in this protocol. 2. male or female subjects who are ≥18 years old at the time of screening (signing the icf): 1. for the younger adult group: 18 to 55 years, inclusive 2. for the older adult group: ≥56 to <80 years 3. have a body mass index (bmi) between 18.5 and 35.0 kg/m2. 4. subjects who are of general good health according to the investigator's assessment, based on a complete medical history without major pathology, and as determined by medical evaluation (including physical examination, electrocardiogram (ecg), vital signs, and clinical laboratory tests). subjects in the older adult population who have medically stable, well-controlled comorbidities may be enrolled at the discretion of the investigator. note: all clinical laboratory values should be within reference ranges unless confirmed by investigator or delegate as not clinically significant. one repeat evaluation of ecg, vital signs, and clinical laboratory tests will be permitted, at the discretion of the investigator. 5. subjects who test negative for hepatitis b surface antigen (hbsag), hepatitis b core antibodies (anti-hbc), anti-hepatitis c virus (hcv) antibodies, and anti-human immunodeficiency virus (hiv) 1 and 2 antibodies at screening. 6. subjects who test negative for sars-cov-2 infection, based on a reverse transcriptase polymerase chain reaction (rt-pcr) test and serological test for sars-cov-2 igm and/or igg antibodies at screening. 7. female subjects are eligible to participate if not pregnant, not breastfeeding, and at least 1 of the following conditions applies: 1. is not a woman of childbearing potential (wocbp), defined as: surgically sterile (documented hysterectomy, bilateral salpingectomy, or bilateral oophorectomy, as confirmed by review of the subject's medical records, medical examination, or medical history interview), or postmenopausal (defined as no menses for 12 months without an alternative medical cause. a high follicle-stimulating hormone [fsh] level in the postmenopausal range may be used to confirm a postmenopausal state in women not using hormonal contraception or hormonal replacement therapy [hrt]. however, in the absence of 12 months of amenorrhea, a single fsh measurement is insufficient). female subjects on hrt and whose menopausal status is in doubt will be required to use 1 of the non estrogen hormonal highly effective contraception methods from day 1 until at least 6 months after the second dose of ip if they wish to continue their hrt during the study. otherwise, they must discontinue hrt to allow confirmation of postmenopausal status before study enrollment. 2. is a wocbp who agrees to use a highly effective method of contraception consistently and correctly from day 1 until at least 6 months after the second dose of ip. 8. nonsterilized male subjects with female partners of childbearing potential are eligible to participate if they agree to one of the following from day 1 until at least 6 months after the second dose of ip and refrain from donating sperm during this period: 1. are abstinent from penile-vaginal intercourse as their usual and preferred lifestyle (abstinent on a long-term and persistent basis) and agree to remain abstinent. 2. agree to use a male condom and have their partner use of a contraceptive method with a failure rate of <1% per year when having penile-vaginal intercourse with a wocbp who is not currently pregnant. 3. male subjects with a pregnant or breastfeeding partner must agree to remain abstinent from penile-vaginal intercourse or use a male condom during each episode of penile penetration.