The hantavirus outbreak on the MV Hondius cruise ship brings a new focus to efforts to develop a vaccine to prevent the virus. Experts say hantavirus vaccine efforts have repeatedly stalled, in part because outbreaks tend to occur sporadically and disproportionately affect poorer countries where there is less incentive for drugmakers to invest. “Our funding agencies don’t put a lot of money into this, because it’s likely not to cause the next epidemic or pandemic,” said Sabra Klein, a professor