Ethics approval
All human studies have been approved by the appropriate ethics committee and have therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. The analysis of the cases was approved by the Duke University Health System Institutional Review Board under the Analysis of possible COVID-19 re-infection protocol (Pro00107410) and the Molecular and Epidemiological Study of Suspected Infection protocol (MESSI, Pro00100241).