Binding and Neutralization Antibody Titers After a Single Vaccine Dose in Health Care Workers Previously Infected With SARS-CoV-2

Current shortages in COVID-19 vaccine production and distribution have led some experts to suggest untested regimens. Persons who have had COVID-19 are thought to have protective immunity and memory responses 2 for at least 6 months; however, neither recall responses nor ideal vaccine dosing regimens have been studied in those previously infected with SARS-CoV-2. We assessed whether health care workers with previous COVID-19 infection could mount recall responses to a single dose of an mRNA-based COVID-19 vaccine.