A unique vaccine produced by the Walter Reed Army Institute of Research started clinical testing Tuesday, and Army researchers hope it will combat variants of SARS-COV-2, the novel coronavirus that causes COVID-19. The vaccine, called spike ferritin nanoparticle, or SpFN, could also help fight other coronaviruses, a group of related RNA viruses that often cause respiratory-related diseases in mammals. Army researchers have been tracking the threat posed by new coronaviruses even before the pandemic, according to Kayvon Modjarrad, director of emerging infectious diseases at Walter Reed. That threat has been accelerating in recent years. “That’s why we need a vaccine like this: one that has potential to protect broadly and proactively against multiple coronavirus species and strains,” Modjarrad said in a statement announcing the SpFN testing.