inclusion criteria: - subjects must meet all of the following inclusion criteria at the screening visit (visit 1) and/or 1st vaccination visit (visit 2) to be eligible for participation in this study. all investigator assessment-based judgments must be carefully and fully documented in the source documents: 1. subjects must have read, understood, and signed the informed consent form (icf) prior to participating in the study; subjects must also complete study-related procedures and must communicate with the study staff at visits and by phone during the study; 2. at the screening visit (visit 1), japanese male and female subjects must be ≥20 years of age; 3. at the screening visit (visit 1) and 1st vaccination visit (visit 2), subject must have a body mass index (bmi) of ≥18.5 kg/m\^2 and \<30 kg/m\^2; 4. subjects are considered by the investigator to be reliable and likely to cooperate with the assessment procedures and be available for the duration of the study; 5. female subjects of childbearing potential must have a negative serum pregnancy test result at the screening visit (visit 1) and a negative urine pregnancy test result at 1st vaccination visit (visit 2): non-childbearing females are defined as: * surgically sterile (defined as bilateral tubal ligation, hysterectomy or bilateral oophorectomy performed more than one month prior to the first study vaccination); or * post-menopausal (absence of menses for 12 consecutive months and age consistent with natural cessation of ovulation); 6. female subjects of childbearing potential must use an effective method of contraception for one month prior to 1st vaccination visit (visit 2) and agree to continue employing highly effective birth control measures for at least one month after the last study vaccination (or in the case of early termination, she must not plan to become pregnant for at least one month after her last study vaccination); 7. subjects must be non-institutionalized (e.g. not living in rehabilitation centers or old-age homes); 8. subjects have no acute or evolving medical problems prior to study participation and no clinically relevant abnormalities that could jeopardize subject safety or interfere with study assessments, as assessed by the principal investigator or sub-investigator (thereafter referred as investigator) and determined by medical history, physical examination, serology, clinical chemistry and hematology tests, urinalysis, and vital signs. investigator discretion is permitted with this inclusion criterion.

inclusion criteria: - subjects must meet all of the following inclusion criteria at the screening visit (visit 1) and/or 1st vaccination visit (visit 2) to be eligible for participation in this study. all investigator assessment-based judgments must be carefully and fully documented in the source documents: 1. subjects must have read, understood, and signed the informed consent form (icf) prior to participating in the study; subjects must also complete study-related procedures and must communicate with the study staff at visits and by phone during the study; 2. at the screening visit (visit 1), japanese male and female subjects must be ≥20 years of age; 3. at the screening visit (visit 1) and 1st vaccination visit (visit 2), subject must have a body mass index (bmi) of ≥18.5 kg/m\^2 and \<30 kg/m\^2; 4. subjects are considered by the investigator to be reliable and likely to cooperate with the assessment procedures and be available for the duration of the study; 5. female subjects of childbearing potential must have a negative serum pregnancy test result at the screening visit (visit 1) and a negative urine pregnancy test result at 1st vaccination visit (visit 2): non-childbearing females are defined as: * surgically sterile (defined as bilateral tubal ligation, hysterectomy or bilateral oophorectomy performed more than one month prior to the first study vaccination); or * post-menopausal (absence of menses for 12 consecutive months and age consistent with natural cessation of ovulation); 6. female subjects of childbearing potential must use an effective method of contraception for one month prior to 1st vaccination visit (visit 2) and agree to continue employing highly effective birth control measures for at least one month after the last study vaccination (or in the case of early termination, she must not plan to become pregnant for at least one month after her last study vaccination); 7. subjects must be non-institutionalized (e.g. not living in rehabilitation centers or old-age homes); 8. subjects have no acute or evolving medical problems prior to study participation and no clinically relevant abnormalities that could jeopardize subject safety or interfere with study assessments, as assessed by the principal investigator or sub-investigator (thereafter referred as investigator) and determined by medical history, physical examination, serology, clinical chemistry and hematology tests, urinalysis, and vital signs. investigator discretion is permitted with this inclusion criterion.

inclusion criteria: - subjects must meet all of the following inclusion criteria at the screening visit (visit 1) and/or 1st vaccination visit (visit 2) to be eligible for participation in this study. all investigator assessment-based judgments must be carefully and fully documented in the source documents: subjects must have read, understood, and signed the informed consent form (icf) prior to participating in the study; subjects must also complete study-related procedures and must communicate with the study staff at visits and by phone during the study; at the screening visit (visit 1), japanese male and female subjects must be ≥20 years of age; at the screening visit (visit 1) and 1st vaccination visit (visit 2), subject must have a body mass index (bmi) of ≥18.5 kg/m^2 and <30 kg/m^2; subjects are considered by the investigator to be reliable and likely to cooperate with the assessment procedures and be available for the duration of the study; female subjects of childbearing potential must have a negative serum pregnancy test result at the screening visit (visit 1) and a negative urine pregnancy test result at 1st vaccination visit (visit 2): non-childbearing females are defined as: surgically sterile (defined as bilateral tubal ligation, hysterectomy or bilateral oophorectomy performed more than one month prior to the first study vaccination); or post-menopausal (absence of menses for 12 consecutive months and age consistent with natural cessation of ovulation); female subjects of childbearing potential must use an effective method of contraception for one month prior to 1st vaccination visit (visit 2) and agree to continue employing highly effective birth control measures for at least one month after the last study vaccination (or in the case of early termination, she must not plan to become pregnant for at least one month after her last study vaccination); subjects must be non-institutionalized (e.g. not living in rehabilitation centers or old-age homes); subjects have no acute or evolving medical problems prior to study participation and no clinically relevant abnormalities that could jeopardize subject safety or interfere with study assessments, as assessed by the principal investigator or sub-investigator (thereafter referred as investigator) and determined by medical history, physical examination, serology, clinical chemistry and hematology tests, urinalysis, and vital signs. investigator discretion is permitted with this inclusion criterion.

inclusion criteria: - subjects must meet all of the following inclusion criteria at the screening visit (visit 1) and/or 1st vaccination visit (visit 2) to be eligible for participation in this study. all investigator assessment-based judgments must be carefully and fully documented in the source documents: subjects must have read, understood, and signed the informed consent form (icf) prior to participating in the study; subjects must also complete study-related procedures and must communicate with the study staff at visits and by phone during the study; at the screening visit (visit 1), japanese male and female subjects must be ≥20 years of age; at the screening visit (visit 1) and 1st vaccination visit (visit 2), subject must have a body mass index (bmi) of ≥18.5 kg/m^2 and <30 kg/m^2; subjects are considered by the investigator to be reliable and likely to cooperate with the assessment procedures and be available for the duration of the study; female subjects of childbearing potential must have a negative serum pregnancy test result at the screening visit (visit 1) and a negative urine pregnancy test result at 1st vaccination visit (visit 2): non-childbearing females are defined as: surgically sterile (defined as bilateral tubal ligation, hysterectomy or bilateral oophorectomy performed more than one month prior to the first study vaccination); or post-menopausal (absence of menses for 12 consecutive months and age consistent with natural cessation of ovulation); female subjects of childbearing potential must use an effective method of contraception for one month prior to 1st vaccination visit (visit 2) and agree to continue employing highly effective birth control measures for at least one month after the last study vaccination (or in the case of early termination, she must not plan to become pregnant for at least one month after her last study vaccination); subjects must be non-institutionalized (e.g. not living in rehabilitation centers or old-age homes); subjects have no acute or evolving medical problems prior to study participation and no clinically relevant abnormalities that could jeopardize subject safety or interfere with study assessments, as assessed by the principal investigator or sub-investigator (thereafter referred as investigator) and determined by medical history, physical examination, serology, clinical chemistry and hematology tests, urinalysis, and vital signs. investigator discretion is permitted with this inclusion criterion.

inclusion criteria: - subjects must meet all of the following inclusion criteria at the screening visit (visit 1) and/or 1st vaccination visit (visit 2) to be eligible for participation in this study. all investigator assessment-based judgments must be carefully and fully documented in the source documents: 1. subjects must have read, understood, and signed the informed consent form (icf) prior to participating in the study; subjects must also complete study-related procedures and must communicate with the study staff at visits and by phone during the study; 2. at the screening visit (visit 1), japanese male and female subjects must be ≥20 years of age; 3. at the screening visit (visit 1) and 1st vaccination visit (visit 2), subject must have a body mass index (bmi) of ≥18.5 kg/m^2 and <30 kg/m^2; 4. subjects are considered by the investigator to be reliable and likely to cooperate with the assessment procedures and be available for the duration of the study; 5. female subjects of childbearing potential must have a negative serum pregnancy test result at the screening visit (visit 1) and a negative urine pregnancy test result at 1st vaccination visit (visit 2): non-childbearing females are defined as: - surgically sterile (defined as bilateral tubal ligation, hysterectomy or bilateral oophorectomy performed more than one month prior to the first study vaccination); or - post-menopausal (absence of menses for 12 consecutive months and age consistent with natural cessation of ovulation); 6. female subjects of childbearing potential must use an effective method of contraception for one month prior to 1st vaccination visit (visit 2) and agree to continue employing highly effective birth control measures for at least one month after the last study vaccination (or in the case of early termination, she must not plan to become pregnant for at least one month after her last study vaccination); 7. subjects must be non-institutionalized (e.g. not living in rehabilitation centers or old-age homes); 8. subjects have no acute or evolving medical problems prior to study participation and no clinically relevant abnormalities that could jeopardize subject safety or interfere with study assessments, as assessed by the principal investigator or sub-investigator (thereafter referred as investigator) and determined by medical history, physical examination, serology, clinical chemistry and hematology tests, urinalysis, and vital signs. investigator discretion is permitted with this inclusion criterion.

inclusion criteria: - subjects must meet all of the following inclusion criteria at the screening visit (visit 1) and/or 1st vaccination visit (visit 2) to be eligible for participation in this study. all investigator assessment-based judgments must be carefully and fully documented in the source documents: 1. subjects must have read, understood, and signed the informed consent form (icf) prior to participating in the study; subjects must also complete study-related procedures and must communicate with the study staff at visits and by phone during the study; 2. at the screening visit (visit 1), japanese male and female subjects must be ≥20 years of age; 3. at the screening visit (visit 1) and 1st vaccination visit (visit 2), subject must have a body mass index (bmi) of ≥18.5 kg/m^2 and <30 kg/m^2; 4. subjects are considered by the investigator to be reliable and likely to cooperate with the assessment procedures and be available for the duration of the study; 5. female subjects of childbearing potential must have a negative serum pregnancy test result at the screening visit (visit 1) and a negative urine pregnancy test result at 1st vaccination visit (visit 2): non-childbearing females are defined as: - surgically sterile (defined as bilateral tubal ligation, hysterectomy or bilateral oophorectomy performed more than one month prior to the first study vaccination); or - post-menopausal (absence of menses for 12 consecutive months and age consistent with natural cessation of ovulation); 6. female subjects of childbearing potential must use an effective method of contraception for one month prior to 1st vaccination visit (visit 2) and agree to continue employing highly effective birth control measures for at least one month after the last study vaccination (or in the case of early termination, she must not plan to become pregnant for at least one month after her last study vaccination); 7. subjects must be non-institutionalized (e.g. not living in rehabilitation centers or old-age homes); 8. subjects have no acute or evolving medical problems prior to study participation and no clinically relevant abnormalities that could jeopardize subject safety or interfere with study assessments, as assessed by the principal investigator or sub-investigator (thereafter referred as investigator) and determined by medical history, physical examination, serology, clinical chemistry and hematology tests, urinalysis, and vital signs. investigator discretion is permitted with this inclusion criterion.