Getty ImagesResearchers say anywhere from 25 percent to 80 percent of people with COVID-19 are unaware they have the virus. There may be a lot of people walking around who have COVID-19 but have no idea they are spreading the virus. In one study, researchers reported that 104 of 128 people (81 percent) on a cruise ship who tested positive the novel coronavirus were asymptomatic. In another study , researchers reported that 42 percent of people who tested positive for COVID-19 were without symptoms. “Of those of us that get symptomatic, it appears that we’re shedding significant virus in our oropharyngeal compartment, probably up to 48 hours before we show symptoms,” Redfield said.