Can Patients Become Reinfected? Reports from China and Japan have indicated that some patients with COVID-19 who were discharged from the hospital after a negative RT-PCR result were readmitted and subsequently tested positive on RT-PCR. It is unclear from the available information if these were true reinfections or the tests were falsely negative at the time of initial discharge. However, while other coronaviruses demonstrate evidence of reinfection, this usually does not happen for many months or years. Therefore, it is unlikely that these were true cases of reinfection. Some reassuring evidence comes from a challenge study among rhesus macaques.4 After initial challenge and clearance of SARS-CoV-2, the animals were rechallenged with the virus but were not infected. While the evidence on reinfection is evolving, current data and experience from previous viruses without substantial seasonal mutation do not support this hypothesis.
