““Putting this all together, Moore and Reiber predicted that the germ would prod people to seek out the company of others early in the infection, before it had blown its cover and triggered a counterattack by defense cells. Once they’d formulated a hypothesis, they decided it would be wise to conduct a pilot trial to see if the idea had any merit. The researchers tracked the social interactions of thirty-six people—none of whom knew the purpose of the study—before and after they got flu shots at a health clinic on the Binghamton campus. The change in the subjects’ behavior was huge, so notable that its magnitude surprised even Reiber and Moore. In the first three days after vaccination, coinciding with the time when the virus was most contagious, subjects interacted with twice as many people as they had before being inoculated. “People who had very limited or simple social lives were suddenly deciding that they needed to go out to bars or parties or invite a bunch of people over,” reported Reiber. “This happened with lots of our subjects. It wasn’t just one or two oddities.””
