Who should receive Tamiflu for swine flu?

The response to the arrival of swine flu in the United Kingdom is unprecedented. In the past, epidemics of infectious diseases have been countered by mass vaccination, never before by mass chemotherapy. Detailed instructions that are modified daily on testing, prophylaxis, and treatment have come from the national Health Protection Agency (HPA) to primary care practitioners via the internet. This strategy could not have been attempted without the internet, and a substantial proportion of the population had to be sufficiently afraid of swine flu for people to readily accept, indeed often demand, a medicine that its prescribers had no previous experience of.

Chemoprophylaxis makes sense when the prophylactic agent is both efficacious and safe, when the disease it is intended to prevent can have serious consequences, and when the epidemic is at a stage when prophylaxis would prevent infection in most of the population until an effective vaccine became available; otherwise it just delays the inevitable. Does experience of the epidemic in the UK support the chemoprophylaxis strategy or is it better to revert to the more conventional one of treating cases as they arise?

Randomised controlled trials provide evidence on the safety and efficacy of neuraminidase inhibitors in the prophylaxis of seasonal flu. Two forms of prophylaxis were tested—prolonged daily dosing regardless of exposure taken throughout the risk period and prophylaxis after household contact with a known case. The reported efficacy was 74% (95% …