evidence: Yale experts answer commonly asked questions about the oral antiviral medication. [...] "Once you’ve been ill with the virus for more than a week, the damage done to the body in a severe case can’t be undone by the antiviral," he says. [...] Some people are thought to be at higher risk because of where they live or work, or because they can’t get health care. This includes many racial and ethnic minorities, and those with disabilities, according to the CDC.