The purpose of this study is to assess the safety, tolerability and PK of Leritrelvir in elder participants

Inclusion Criteria:

1. Signature of a dated Informed Consent Form (ICF) indicating that the participates has been informed of all the relevant aspects(including adverse events) of the trial prior to enrollment.

2. Participants must be willing and able to adhere to the visit schedule and protocol requirements and be available to complete the study.

3. Body weight is no less than 50 kg in males and no less than 45 kg in females. Body mass index (BMI) 18≤BMI<28 kg/m2,BMI is determined by the following equation: BMI = weight/height2 (kg/m2).

4. Heart rate between 50-100 beats/min, Body temperature between 35.7-37.5℃

   Young Participants Only:

5. Participant must be ≥18 to ≤45 years old

   Elder Participants Only:

6. Participant must be ≥65 years old

Exclusion Criteria:

1. Participants with an allergic disposition (multiple drug and food allergies)

2. Participants who donated blood or bleeding profusely (> 400 mL) in the 3 months.

3. Participants with clinically significant disease, such as gastrointestinal disease, infection (e.g., respiratory or central nervous system infection),within 2 weeks before screening;

4. Participants who could not tolerate blood collection by venipuncture and/or had a history of dizzy with blood and needles

   Young Participants Only:

5. Participants had taken or planned to take any prescription medication, over-the-counter medication, vitamin product, or herbal medicine within 2 weeks before screening;

6. Physical examination, vital signs, laboratory tests (blood routine+CRP, urine routine + urine sediment, blood biochemistry, coagulation function, infectious disease test, glycosylated hemoglobin test), 12-lead electrocardiogram, chest CT, abdominal color Doppler ultrasound and other examinations have clinical significance

   Elder Participants Only:

7. Participants had a history of or evidence of cardiovascular disease before screening，including uncontrolled hypertension, orthostatic hypotension, severe arrhythmia, heart failure, Adams-stokes syndrome, unstable angina, myocardial infarction within the past 6 months before screening, or history of tachycardia/bradycardia requiring medical treatment, and degree II-III atrioventricular block.

8. Participants who had other serious organ-systemic serious diseases at screening, including but not limited to respiratory, neurologic, hematologic, endocrine, oncologic, immunologic, psychiatric, or cardiocerebrovascular diseases, and was judged by the investigator to be ineligible for participation in the trial