a slight slowdown of the spread, but that's not entirely clear. Quarantines and travel restrictions haven't helped with previous flu transmission. It backfired entirely on the cruise ship.
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In 2009, the influenza virus H1N1 went pandemic; other countries banned travel from North America, its apparent point of origin. China detained and quarantined planeloads of people. “Not only did it not work, but it likely exacerbated the pandemic,” Nuzzo says. (Getting confined with people who might be sick is a good way to get sick yourself, as any parent who stays home with a germy kid can tell you—and respiratory viruses are particularly good at this kind of hospital-based “nosocomial” infection.) One 2011 study by a team of modelers in Europe and the US said that H1N1 travel bans reduced air travel to and from Mexico by 40 percent—with huge economic consequences—but didn’t slow the disease’s spread at all. A 2014 British meta-analysis of 23 different studies of the effect of travel restrictions on influenza outbreaks concluded that they slowed disease spread by no more than 3 percent—less if the restrictions came late in the outbreak, and less in big cities.