When deadly bird flu strikes, six degrees of separation could be the distance from here to hell. Even if a vaccine is found to be effective, it may be impossible to produce enough shots for everybody quickly enough, so authorities would have to decide how to use the doses they have in the most effective way. Researchers are now proposing a new strategy for targeting shots that could, at least in theory, stop a pandemic from spreading along the network of social interactions.
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Vaccinating selected people is essentially equivalent to cutting out nodes of the social network. As far as the pandemic is concerned, it’s as if those people no longer exist. The team’s idea is to single out people so that immunizing them breaks up the network into smaller parts of roughly equal sizes. Computer simulations show that this strategy could block a pandemic using 5 to 50 percent fewer doses than existing strategies, the researchers write in an upcoming Physical Review Letters.
“The strategy is to disintegrate the network,” says study coauthor Shlomo Havlin of Bar-IlanUniversity in Ramat-Gan, Israel. Havlin and his collaborators say their method could also offer a cost-effective way of blocking the spread of computer viruses on the Internet, or breaking up a terrorist network.