The sample size calculation in the original protocol assumed that approximately 70% of subjects would be confirmed as having influenza A or B infection, meaning that a total of 636 subjects would be required, in order to provide the target sample size of 444 influenza-infected subjects. However, of the first 105 subjects enrolled in this study, only 48 (45.7%) were confirmed as being infected with influenza. Additionally, the enrolment rate into the pharmacokinetic (PK) sub-study has been very low. In order to address this, Biota has made three key changes to the protocol: • Previously, subjects were eligible if they had either (a) a measured fever at screening or (b) they had a self-reported history of fever within the past 24 hours and they had taken anti-pyretic medication within 6 hours of screening. However, out of the first 105 subjects enrolled in this study, a subset of 42 subjects had a measured temperature of ≥38.0°C at screening. Of those, 27 (64.3%) were confirmed as being infected with influenza, compared to 21/63 (33.3%) who did not have a measured fever at screening. This suggests that a measured fever at screening is strongly predictive of influenza infection. Consequently, for the remainder of the study, subjects will only be eligible if they have a measured fever at the screening visit. • To mitigate the risk of completing the study with fewer than the target number of influenza-positive subjects, the study will now aim to recruit up to 900 randomized or 444 laboratory-confirmed influenza infected subjects, whichever occurs first. This means that if the upper limit of 900 randomized subjects is reached first, the target sample size would still be achieved if approximately 50% of enrolled subjects have laboratory-confirmed influenza A or B infection. • The number of sites participating in the PK sub-study will be substantially increased, and the cap on the number of subjects who can participate in the sub-study has been removed.