A Study to Learn About the Study Medicine PF-07321332 and Ritonavir in Adult Healthy Chinese Participants.

Accumulation ratio for AUCtau following multiple dosing was calculated as AUCtau on Day 10 divided by AUC12 on Day 1.

Time frame: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours); Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Observed accumulation ratio for Cmax was calculated as Cmax on Day 10 divided by Cmax on Day 1.

Time frame: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours); Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Apparent oral clearance. This was determined by Dose/AUCtau.

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Apparent oral volume of distribution.

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Area under the plasma concentration-time profile from time 0 to the time of the last quantifiable concentration (Clast)

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24 and 48 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Area under the plasma concentration-time profile from time Zero to time point on 12 hours

Time frame: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Area under the plasma concentration-time profile from time 0 to the time of the end of the dosing interval (tau), where tau=12 hours.

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

This was determined by AUCtau/tau.

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Cmax is maximum plasma concentration .

Time frame: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Cmax is maximum plasma concentration

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

This was determined by Day 10 Cmax/Day 10 Ctrough.

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Terminal half-life. This was determined by Loge(2)/kel, where kel is the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve.

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24 and 48 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Tmax is the time for maximum plasma concentration

Time frame: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Tmax is the time for maximum plasma concentration

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Concentration at 12 hour time on Day 10. Observed directly from data.

Time frame: Day 10 (12 hours after last dose)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Concentration at pre-dose on Day 10. Observed directly from data.

Time frame: Day 10 (pre-dose)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Concentration at pre-dose on Day 5. Observed directly from data.

Time frame: Day 5 (pre-dose)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Concentration at pre-dose on Day 8. Observed directly from data.

Time frame: Day 8 (pre-dose)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

The average of the triplicate readings collected at each assessment time was calculated for each ECG parameter. Baseline was defined as the average of the triplicate pre-dose recordings on Day 1. Pre-defined categories for corrected QT (Fridericia method) (QTcF): Absolute value (milliseconds\[msec\]) \>450 and ≤480, or \>480 and ≤500, or \>500; Increase from baseline in QTcF (msec) \>30 and ≤60, or\>60. Pre-defined categories for PR and QRS: PR (msec) max. ≥300; PR (msec) increase from baseline: baseline \>200 and max. ≥25% increase, or baseline ≤200 and max. ≥50% increase; QRS (msec) max. ≥140; QRS (msec) increase from baseline ≥50% increase. Participants who met at least 1 pre- specified criteria would be reported in outcome measure.

Time frame: Day 1 (pre-dose, within 1-2 hours after morning dose), Day 10 (pre-dose, within 1-2 hours after morning dose)

Population: The analysis population included all participants who took at least 1 dose of study intervention.

Safety laboratory assessments included hematology, urinalysis, and clinical chemistry.

Time frame: Day-1, Day 2, Day 5, Day 8, Day 10, Day 12.

Population: The analysis population included all participants who took at least 1 dose of study intervention.

An adverse event (AE) is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. A serious AE was any untoward medical occurrence at any dose that resulted in death; was life-threatening; required hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability/incapacity; resulted in congenital anomaly/birth, was a suspected transmission via a Pfizer product of an infectious agent,pathogenic or non-pathogenic. An adverse event is considered a Treatment-Emergent Adverse Event (TEAE) if the event started during the effective duration of treatment. All events that started on or after the first dosing day and time/start time, if collected, but before the end of the study would be flagged as TEAEs.

Time frame: From baseline up to Day 42

Population: The analysis population included all participants who took at least 1 dose of study intervention.

Vital signs evaluations included supine blood pressure (BP) and pulse rate. The pre specified criteria for vital signs included systolic blood pressure (BP) minimum (min.) less than (\<) 90 millimeter of mercury (mmHg); systolic BP change from baseline maximum (max.) decrease \>= 30 mmHg, max. increase \>=30 mmHg; diastolic BP min. \<50mmHg; diastolic BP change from baseline max. decrease \>=20, max. increase \>=20; seated pulse rate min. \<40 beats per minute (bpm) and max. \>120 bpm. Participants who met at least 1 pre- specified criteria would be reported in outcome measure.

Time frame: Day 1 (pre-dose, within 1-2 hours after morning dose), Day 10 (pre-dose, within 1-2 hours after morning dose)

Population: The analysis population included all participants who took at least 1 dose of study intervention.

Apparent oral clearance. This was determined by Dose/AUCtau.

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Apparent oral volume of distribution. This was determined by Dose/(AUCtau\*kel)

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Area under the plasma concentration-time profile from time 0 to the time of the last quantifiable concentration (Clast)

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24, and 48 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

This was determined by linear/Log trapezoidal method - reported as AUC12 on Day 1.

Time frame: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Area under the plasma concentration-time profile from time 0 to the time of the end of the dosing interval (tau), where tau=12 hours.

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

This was determined by AUCtau/tau.

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Cmax is maximum plasma concentration

Time frame: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Cmax is maximum plasma concentration

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Terminal half-life. This was determined by Loge(2)/kel, where kel is the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve.

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8, 12, 24, and 48 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Tmax is the time for maximum plasma concentration

Time frame: Day 1 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Tmax is the time for maximum plasma concentration

Time frame: Day 10 (pre-dose, 0.5, 1, 1.5, 2, 4, 6, 8 and 12 hours)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Concentration at 12 hour on Day 10. Observed directly from data.

Time frame: Day 10 (12 hours after last dose)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Concentration at pre-dose on Day 10. Observed directly from data.

Time frame: Day 10 (pre-dose)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Concentration at pre-dose on Day 5. Observed directly from data.

Time frame: Day 5 (pre-dose)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.

Concentration at pre-dose on Day 8. Observed directly from data.

Time frame: Day 8 (pre-dose)

Population: The pharmacokinetic (PK) parameter analysis set was defined as all participants assigned to investigational product and treated who had at least 1 of the PK parameters of primary interest measured.