evidence: You also qualify if you have certain underlying conditions or lifestyle factors that could increase the risk of progression to severe disease. Pfizer estimates that roughly 75% of adults in the U.S. have at least one risk factor, which could include a condition such as cancer, diabetes, heart disease, pregnancy, a weakened immune system, or a mental health disorder. Adults are also at higher risk if they are unvaccinated or not up to date on their COVID vaccinations (although even if you are vaccinated, Paxlovid can provide additional protection).