Prophylaxis or treatment? Optimal use of an antiviral stockpile during an influenza pandemic.

We introduce a novel mathematical model that effectively incorporates contact tracing in a realistic distribution mechanism for antiviral drugs in an influenza pandemic scenario. A strategy focused on targeted provision of post-exposure prophylaxis, rather than treatment, will provide the greatest chance of minimising the impact of an influenza pandemic. Targeted post-exposure prophylaxis delays the onset of the pandemic and for a wide range of parameter values, a delay of the order of 6-18 months may be achievable. This may provide enough time to develop and distribute a vaccine. In contrast, a treatment based strategy typically does not delay the onset of a pandemic by an appreciable amount and, in general, is not capable of significantly reducing the attack rate from baseline.