In the final scene of the 2011 blockbuster film
Rise of the Planet of the Apes
, a pilot unwittingly carries a dangerous flu virus from San Francisco to Paris. From there, countless air passengers spread it around the world. Unlike the apes, a large proportion of humanity does not survive the subsequent pandemic.
Of course, this was pure science fiction, but the spread of infectious viruses via air travel is a real risk. Researchers from the ETH Professorship of Computational Social Science and a collaborator from the ETH Department of Computer Science have investigated how network dismantling could help containing the global spread of viruses through air transport more cost-effectively.
A protective measure, which is sometimes discussed, is to close certain airports and put them under quarantine. Then, one option would be to focus on the world’s largest airport hubs with most flight connections – after all, a large number of passengers land there or change planes. This might actually not be the best idea.
The intervention would be massive due to the large number of passengers involved. In the scientific journal
PNAS
, ETH researchers Xiao-Long Ren, Niels Gleinig, Dirk Helbing and Nino Antulov-Fantulin have now been able to show that there might be less radical and more effective ways to achieve the same level of protection, affecting much fewer passengers.
Start with the medium-sized ones
“For example, if you would close down a few medium-sized airports first instead of the largest hubs, it would cost four times less in the scenario we studied, but it appears to be just as effective in containing the spread of a virus,” says Nino Antulov-Fantulin.
The ETH researchers explored this scenario for Europe, North America and Asia as parts of the worldwide air traffic network. Their results show that the closure of medium-sized airports would affect only 6 percent of global air passengers, while closing the largest hubs would affect 25 percent.