Johns Hopkins’s Center for Immunization Research is enrolling otherwise healthy medical subjects to be injected and infected with Zika, the virus associated with microcephaly that created a global panic in 2015-2016.

Undoubtedly, care is being taken so that Zika won’t escape, via sexual activity or an unseen mosquito bite by locally endemic Aedes albopictus, to cross-infect and contaminate the region. But even with precautions in place, the question arises: Why are government-funded investigators, six years after the Zika epidemic vanished, deliberately infecting U.S. citizens now?