"Yes, we can prepare, but with the realization that no amount of hand washing, hand wringing, public education, or gauze masks will do the trick. The keystone of influenza prevention is vaccination. It is unreasonable to believe that we can count on prophylaxis with antiviral agents to protect a large, vulnerable population for more than a few days at a time, and that is not long enough. How long will they be given? To whom? What are the risks in mass administration? All of this is unknown. But vaccination against what? We do not know. Perhaps against H5N1. But do we not already have a vaccine? No, we do not; no vaccine of adequate antigenic potency is available in sufficient supply. The answer lies in an approach first suggested at a World Health Organization meeting in 1969 and repeatedly endorsed since by virtually every pandemic preparedness planning group. This recommendation assumes that the nature of the next pandemic virus cannot be predicted, but that it will arise from 1 of the 16 known HA subtypes in avian or mammalian species. Accordingly, preparation by genetic reassortment of high-yield seed viruses of all HA subtypes should proceed as soon as possible for potential use in vaccine production. Thirty-seven years later, this goal has not yet been achieved."