According to People’s Daily, Liang Zong’an, director of the Department of Respiratory and Critical Care Medicine at West China Hospital of Sichuan University, said that patients produce protective antibodies within a certain period of time after infection, and are relatively safe for a period of time (generally speaking, a few months). But over a long period of time, it cannot be ruled out that the type of virus mutates or that even the same type of virus can be infected. Source: People’s Daily, “Can cured patients be infected twice?