A Prospective Study to Examine the Effectiveness and Safety of Antivirals in Volunteers Who Receive Short-term Prophylaxis Against Pandemic Influenza

The aim of this study is to 1. Describe the effectiveness of short-term prophylaxis against symptomatic pandemic influenza infection 2. Describe the safety of short-term prophylaxis 3. Describe the seroconversion rate against pandemic influenza among recipients of short-term prophylaxis The study is an open label prospective cohort study. Contact group members of people with diagnosed influenza who are recommended to receive NA inhibitor prophylaxis for short periods of time will be enrolled following provision of informed consent. Each episode of short-term prophylaxis will be recorded separately. By design it is hoped that volunteers in this study who develop symptoms and signs of pandemic influenza infection will be enrolled in the Index Case (PIPET A) protocol with follow-up as required.