Inclusion Criteria:  Japanese Healthy adults aged ≥20 and ≤50 years (Step 1) or healthy elderly aged ≥65 and ≤80 years (at the time of informed consent) Body mass index (BMI) is ≥18.0 and <30.0 kg/m^2 (at screening)  Exclusion Criteria:  Participants with a history of anaphylaxis or severe allergies due to food, medicine, insect bites, cosmetics, or vaccination Having alcohol or drug dependence, etc.