1. provide written informed consent before the first study-specific procedure - 19~54 years, Male and Female (Step 1 (Phase I)) - 19~85 years, Male and Female (Step 2 (Phase IIa)) 2. Participants must have a body mass index (BMI) between =18.5 and =30.0 kg/m2 at screening 3. Must agree to use highly effective, medically accepted double-barrier contraception (both male and female partners) from screening until study completion (until 3 months after second vaccination) as specified below in this criterion 4. Must agree not to donate blood or transfusion (including whole blood, plasma, and platelet components)

1. provide written informed consent before the first study-specific procedure - 19~54 years, Male and Female (Step 1 (Phase I)) - 19~85 years, Male and Female (Step 2 (Phase IIa)) 2. Participants must have a body mass index (BMI) between =18.5 and =30.0 kg/m2 at screening 3. Must agree to use highly effective, medically accepted double-barrier contraception (both male and female partners) from screening until study completion (until 3 months after second vaccination) as specified below in this criterion 4. Must agree not to donate blood or transfusion (including whole blood, plasma, and platelet components)