Participants assessed the severity of 7 influenza-associated symptoms (cough, sore throat, headache, nasal congestion, feverishness/chills, muscle/joint pain, and fatigue) on a 4-point scale (0 = no symptoms, 1= mild, 2 = moderate, and 3 = severe). Time to improvement of symptoms was defined as the time from the start of treatment to the time when all influenza symptoms were alleviated, maintained, or improved, as defined below, for a duration of at least 21.5 hours:

• Preexisting symptoms (cough, fatigue, or muscle/joint pain that existed prior to influenza) that were worse at baseline must have improved at least 1 point from baseline
• Preexisting symptoms not worse at baseline must have maintained baseline severity
• New symptoms must have alleviated, defined as a symptom score of none (0) or mild (1).

Time to improvement of symptoms was analyzed using Kaplan-Meier (KM) methods; participants who did not experience improvement of symptom s were censored at the last observation.

Participants in the intention-to-treat infected population with available time to improvement of symptoms data.

Virus titer was quantified from nasopharyngeal swabs (or throat swabs if nasopharyngeal swabbing was not feasible) using tissue culture methods. Positive influenza virus titer was defined as virus titer not less than the lower limit of quantification (0.7 log₁₀ of the 50% tissue culture infective dose (TCID₅₀/mL) among those assessed for virus titer on Days 2, 3, 4, 5, 6, and 9.

Participants in the intention-to-treat infected population with a positive influenza virus titer on Day 1 and with available virus titer data at each time point.

Influenza virus ribonucleic acid (RNA) was quantified from nasopharyngeal swabs (or throat swabs, if nasopharyngeal swabbing was not feasible). The percentage of participants with detectable virus RNA (2.05 for flu A and 2.83 for flu B log₁₀ virus particles/mL) measured by reverse transcription polymerase chain reaction (RT-PCR) among those assessed on Days 2, 3, 4, 5, 6 and 9.

Participants in the intention-to-treat infected population with positive influenza virus RNA determined by RT-PCR on Day 1 and with available data at each time point.

Virus titer was quantified from nasopharyngeal swabs (or throat swabs if nasopharyngeal swabbing was not feasible) by tissue culture methods.

If virus titer was less than the lower limit of quantification, the virus titer was imputed 0.7 (TCID₅₀/mL).

Participants in the intention-to-treat infected population with positive influenza virus titer on Day 1 and with available virus titer data at each time point.

Nasopharyngeal swabs (or throat swabs, if nasopharyngeal swabbing was not feasible) were obtained for viral quantitation. Virus RNA was measured by reverse transcription polymerase chain reaction (RT-PCR).

Participants in the intention-to-treat infected population with positive RT-PCR on Day 1 and with available virus RNA data at each time point.

This endpoint was defined as AUC of change from Baseline in virus titer from Day 1 to Day 9. AUC was calculated using the trapezoidal method.

Participants in the intention-to-treat infected population with a positive virus titer on Day 1 and available sample on Day 9.

This endpoint was defined as AUC of change from baseline in the amount of virus RNA (RT-PCR) from Day 1 to Day 9. The AUC was calculated using the trapezoidal method.

Participants in the intention-to-treat infected population with a positive virus RNA determined by RT-PCR at baseline and available sample on Day 9.

Time to cessation of viral shedding by virus titer was defined as the time between the initiation of the study treatment and first time when the virus titer was below the limit of detection (0.7 log₁₀[TCID₅₀/mL]). The median and 95% confidence interval (CI) for time to cessation of viral shedding determined by virus titer was analyzed using the Kaplan-Meier (KM) method; participants whose virus titer had not reached cessation by the last observation time point were treated as censored at that time point.

Participants in the intention-to-treat infected population with a positive virus titer on Day 1 whose time to cessation of viral shedding by virus titer was not missing.

Time to cessation of viral shedding by RT-PCR was defined as the time between the initiation of the study treatment and first time when the virus RNA was below the limit of detection measured by RT-PCR.

Time to cessation of viral shedding by RT-PCR was analyzed using the KM method; participants whose virus RNA had not reached cessation by the last observation time point were treated as censored at that time point.

Participants in the intention-to-treat infected population with positive influenza virus RNA determined by RT-PCR on Day 1 whose time to cessation of viral shedding by RT-PCR.

Participants assessed the severity of 7 influenza-associated symptoms (cough, sore throat, headache, nasal congestion, feverishness or chills, muscle or joint pain, and fatigue) on a 4-point scale (0 = no symptoms, 1= mild, 2 = moderate, and 3 = severe).

Improvement of symptoms was defined as all influenza symptoms alleviated, maintained, or improved, as defined below, for a duration of at least 21.5 hours:

• Preexisting symptoms (cough, fatigue, or muscle/joint pain that existed prior to influenza) judged to be worse at baseline must have improved at least 1 point from baseline severity
• Preexisting symptoms judged not to be worse at baseline must have maintained baseline severity
• New symptoms at baseline must have alleviated, defined as a symptom score of none (0) or mild (1).

Participants in the intention-to-treat infected population with available symptoms data at each time point.

Participants assessed the severity of seven influenza-associated symptoms (cough, sore throat, headache, nasal congestion, feverishness or chills, muscle or joint pain, and fatigue) on a 4-point scale (with 0 indicating no symptoms, 1 mild symptoms, 2 moderate symptoms, and 3 severe symptoms).

Time to alleviation of symptoms was defined as the time from the start of the study treatment to the time when all seven influenza-related symptoms were assessed by the participant as absent (0) or mild (1) for at least 21.5 hours.

Time to alleviation of symptoms was analyzed using Kaplan-Meier (KM) methods; participants who did not experience alleviation of symptoms were censored at the last observation time point.

Participants in the intention-to-treat infected population with available time to alleviation of symptoms data.

Participants assessed the severity of 7 influenza-associated symptoms on a 4-point scale (from 0 = no symptoms to 3 = severe symptoms). Time to improvement of the 4 systemic symptoms was defined as the time between the initiation of study treatment to the time when all 4 systemic symptoms (headache, feverishness or chills, muscle or joint pain, and fatigue) were alleviated, maintained, or improved, as defined below, for a duration of at least 21.5 hours:

• Preexisting symptoms (cough, fatigue, or muscle/joint pain that existed prior to influenza) that were worse at baseline must have improved at least 1 point from baseline
• Preexisting symptoms not worse at baseline must have maintained baseline severity
• New symptoms at baseline must have alleviated, defined as a symptom score of none (0) or mild (1).

Time to improvement of the 4 systemic symptoms was analyzed using KM methods; participants who did not experience improvement of symptoms were censored at the last observation.

Participants in the intention-to-treat infected population with available time to improvement of the 4 systemic symptoms data.

Participants assessed the severity of 7 influenza-associated symptoms on a 4-point scale (from 0 = no symptoms to 3 = severe symptoms). Time to improvement of the 3 respiratory symptoms was defined as the time from the start of study treatment to the time when all 3 respiratory symptoms (cough, sore throat, and nasal congestion) were alleviated, maintained, or improved, as defined below, for a duration of at least 21.5 hours:

• Preexisting symptoms (cough, fatigue, or muscle/joint pain that existed prior to influenza) that were worse at baseline must have improved at least 1 point from baseline
• Preexisting symptoms not worse at baseline must have maintained baseline severity
• New symptoms at baseline must have alleviated, defined as a symptom score of none (0) or mild (1).

Time to improvement of the 3 respiratory symptoms was analyzed using KM methods; participants who did not experience improvement of symptoms were censored at the last observation time point.

Participants in the intention-to-treat infected population with available time to improvement of the 3 respiratory symptoms data.

Time to resolution of fever was defined as the time between the initiation of the study treatment and the resolution of fever. The resolution of fever was defined as the time when the participant's self-measured axillary temperature became less than 37ºC and was maintained at less than 37ºC for at least 12 hours. Time to resolution of fever was analyzed using KM methods; participants who did not experience resolution of fever by the last observation time point were censored at that time point.

Participants in the intention-to-treat infected population whose body temperature at baseline was more than 37°C and time to resolution of fever was not missing

Defined as the percentage of patrticipants whose axillary body temperature dropped to less than 37ºC after the initiation of the study treatment.

Participants in the intention-to-treat infected population whose body temperature at baseline was more than 37°C and with available body temperature data at each time point.

Participant's self-measured axillary temperature using an electronic thermometer.

Participants in the intention-to-treat infected population with available temperature data at each time point.

Participants assessed the severity of 7 influenza-associated symptoms on a 4-point scale (0 = no symptoms to 3 = severe). Time to improvement of cough, fatigue, and muscle/joint pain was defined as the time from the start of treatment to the time when each symptom was alleviated, maintained, or improved, as defined below, for at least 21.5 hours:

• Preexisting symptoms that were worse at baseline must have improved at least 1 point from baseline
• Preexisting symptoms not worse at baseline must have maintained baseline severity
• New symptoms must have alleviated, defined as a score of 0 (None) or 1 (Mild). Time to improvement of sore throat, headache, nasal congestion, and feverish/chills was defined as the time from the start of treatment to the time when the symptom was assessed as 0 (None) or 1 (Mild) for at least 21.5 hours.

Time to improvement of symptoms was analyzed using KM methods; participants with no improvement of symptoms were censored at the last observation.

Participants in the intention-to-treat infected population; the analysis of each individual symptom includes participants with new or preexisting and worsened symptom scores of moderate (2) or severe (3) at baseline, and with available time to improvement of symptom data.

Participants were asked to record their preinfluenza health status on a scale from 0 (worst possible health) to 10 (normal health [for someone your age and condition]), and their health status at baseline and every day after initiation of study treatment on the same scale. Return to preinfluenza health status was defined as time from the initiation of the study treatment to the first time when the health status score was equal to or higher than the preinfluenza health status score.

Time to return to preinfluenza health status was analyzed using KM methods; participants with a smaller number on the scale for health status by the last observation time point were censored at that time point.

Participants in the intention-to-treat infected population whose health status score at baseline was lower than the preinfluenza health status score and with available time to return to preinfluenza health status data.

The percentage of participants who received systemic antibiotics for any of the predefined complications (sinusitis, otitis media, bronchitis and pneumonia).

Intention-to-treat infected population

Defined as the percentage of patients who experience each influenza-related complication (hospitalization, death, sinusitis, otitis media, bronchitis, and radiologically-confirmed pneumonia) as an adverse event after the initiation of study treatment.

Intention-to-treat population

All participants who received at least 1 dose of study drug