Dose, Safety, and Pathogenicity of a New Influenza A H3N2 Challenge Strain

Occurrence of adverse events (AEs) related to the viral challenge from viral challenge (Day 0) to the Day 28 follow-up visit.

Occurrence of serious adverse events (SAEs) related to the viral challenge from viral challenge (Day 0) to the Day 28 follow-up visit.

Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR)-confirmed influenza infection, defined as 2 quantifiable (≥ lower limit of quantification [LLOQ]) qRT-PCR measurements (reported over 4 planned consecutive assessments within 48 hours), from Day 1 pm to planned discharge from quarantine (Day 8 am).

Viral culture-confirmed influenza infection, defined as a quantifiable viral culture measurement, from Day 1 pm to planned discharge from quarantine (Day 8 am).

Area under the viral load-time curve (VL-AUC) of influenza challenge virus as determined by qRT-PCR on both nasal and throat (Part B only) samples, starting from Day 1 pm up to planned discharge from quarantine (Day 8 am)

Peak viral load of influenza challenge virus defined as the maximum viral load, from qRT-PCR on nasal and throat (Part B only) samples from Day 1 pm to planned discharge from quarantine (Day 8 am).

Area under the viral load-time curve (VL-AUC) of influenza challenge virus as determined by viral culture on both nasal and throat (Part B only) samples, starting from Day 1 pm up to planned discharge from quarantine (Day 8 am)

Peak viral load of influenza challenge virus defined as the maximum viral load, from by viral culture on nasal and throat (Part B only) samples from Day 1 pm to planned discharge from quarantine (Day 8 am).

Data presented is score*days. TSS-AUC (trapezium rule) as measured by graded symptom scoring system collected 3 times daily starting Day 1 am up to Day 8 am using a participant self-reportable 13-symptoms card, the max number of diary cards included in the AUC calculation is 22, the maximum time period is 7 days.

Clinical symptoms included runny nose, stuffy nose, sneezing, sore throat, earache, malaise/tiredness, headache, muscle and/or joint ache, chilliness/feverishness, cough, chest tightness, shortness of breath, and wheeze. Participants scored symptom from 0 (no symptoms) to 3 (severe). Shortness of breath and wheeze had an additional scoring option of grade 4.

Dairy card total symptom scores ranged from 0 (if all symptoms graded 0) to 41 (if all symptoms graded 3 and shortness of breath and wheeze graded 4).

The range of TSS AUC scores are between 0 and 287 score*days (maximum of 41*7).

Peak Total Symptom Score (TSS) for each participant is defined as the diary card total with the worst score (highest). The symptom scoring system was collected three times daily starting one day post-viral challenge (Day 1) up to discharge from quarantine (Day 8 am) using a participant self-reportable 13-symptoms card.

Clinical symptoms included runny nose, stuffy nose, sneezing, sore throat, earache, malaise/tiredness, headache, muscle and/or joint ache, chilliness/feverishness, cough, chest tightness, shortness of breath, and wheeze. Participants scored symptom from 0 (no symptoms) to 3 (severe). Shortness of breath and wheeze had an additional scoring option of grade 4.

Dairy card total symptom scores ranged from 0 (if all symptoms graded 0) to 41 (if all symptoms graded 3 and shortness of breath and wheeze graded 4).

Peak daily symptom score was derived, for each day from Day 1 to Day 8, as the maximum of the 3 total symptoms scores on that day. The symptoms were collected three times daily starting one day post-viral challenge (Day 1) up to planned discharge from quarantine (Day 8 am) using a participant self-reportable 13-symptoms card.

Clinical symptoms included runny nose, stuffy nose, sneezing, sore throat, earache, malaise/tiredness, headache, muscle and/or joint ache, chilliness/feverishness, cough, chest tightness, shortness of breath, and wheeze. Participants scored symptom from 0 (no symptoms) to 3 (severe). Shortness of breath and wheeze had an additional scoring option of grade 4.

Dairy card total symptom scores ranged from 0 (if all symptoms graded 0) to 41 (if all symptoms graded 3 and shortness of breath and wheeze graded 4).

A qRT-PCR-confirmed influenza infection, defined as 2 quantifiable (≥LLOQ) qRT-PCR measurements (reported on 2 or more independent samples over 4 planned consecutive assessments within 48 hours), from Day 1 pm to planned discharge from quarantine (Day 8 am) AND, a febrile episode, defined as a temperature of ≥37.9°C, from Day 1 am to planned discharge from quarantine (Day 8 am).

A qRT-PCR-confirmed influenza infection, defined as 2 quantifiable (≥LLOQ) qRT-PCR measurements (reported on 2 or more independent samples over 4 planned consecutive assessments within 48 hours), from Day 1 pm to planned discharge from quarantine (Day 8 am) AND, a febrile episode, defined as a temperature of ≥37.8ºC, and a cough and/or sore throat (symptoms and signs), from Day 1 am to planned discharge from quarantine (Day 8 am), in the absence of a known cause other than influenza.

A qRT-PCR-confirmed influenza infection, defined as 2 quantifiable (≥LLOQ) qRT-PCR measurements (reported on 2 or more independent samples over 4 planned consecutive assessments within 48 hours), from Day 1 pm to planned discharge from quarantine (Day 8 am) AND, a febrile episode, defined as a temperature of ≥38.0ºC and a cough, from Day 1 am to planned discharge from quarantine (Day 8 am).

A qRT-PCR-confirmed influenza infection, defined as 2 quantifiable (≥LLOQ) qRT-PCR measurements (reported on 2 or more independent samples over 4 planned consecutive assessments within 48 hours), from Day 1 pm to planned discharge from quarantine (Day 8 am) AND, any symptoms from the symptom diary card of grade ≥2 at a single time point, from Day 1 am to planned discharge from quarantine (Day 8 am).

A qRT-PCR-confirmed influenza infection, defined as 2 quantifiable (≥LLOQ) qRT-PCR measurements (reported on 2 or more independent samples over 4 planned consecutive assessments within 48 hours), from Day 1 pm to planned discharge from quarantine (Day 8 am) AND, a total symptom score of ≥2 at a single time point, from Day 1 am to planned discharge from quarantine (Day 8 am).

Viral culture laboratory-confirmed infection, AND any symptoms from the symptom diary card of grade ≥2 at a single time point, from Day 1 am to planned discharge from quarantine (Day 8 am).