Whether one worries about limited supplies of vaccines during the flu season, or about what might be needed in the event of a biological attack, it seems a good idea to think about how to optimize the distribution of such protection. Reuven Cohen of Bar-Ilan University in Israel and colleagues have made an amazingly simple suggestion: choose, at random, a sample of the population, ask them to name one acquaintance and then vaccinate those acquaintances.
The idea is that the people who are most likely to spread the disease, due to their large number of associates, have a high probability of being named. This overcomes the problem that those who have many acquaintances tend to be fewer in number and therefore unlikely to be chosen in a random trial. While this is clearly of medical interest, its application in protecting computers from viral attack by distributing suitable patches is also clear.
Further reading
R Cohen et al. 2003 Phys. Rev. Lett. 91 247901.