Incidence of COVID-19 recurrence among large cohort of healthcare employees

Purpose: To quantify COVID-19 recurrence among clinical and nonclinical healthcare employees with SARS-CoV-2 IgG antibodies or prior COVID-19 infection. Methods: This prospective, cohort study collected and resulted SARS-CoV-2 IgG serum samples as positive or negative from June 8 to July 10, 2020 from a convenience sample of 16,233 adult participants employed by a large Midwestern healthcare system. Documented positive polymerase chain reaction test results representing COVID-19 infections were recorded up to four months prior to and post-IgG testing. Results: Nine hundred and thirteen (6.12%) participants, including 45 (4.93%) IgG positive participants, experienced COVID-19 infections after study initiation, representing a 51% increased risk of COVID-19 infection among IgG positive participants (IRR = 1.51). Regressions adjusted for documented disparities showed no difference in COVID-19 infection by IgG status (OR = 1.19; P = .3117) but significantly greater odds in COVID-19 recurrence among participants with a prior documented COVID-19 infection (OR = 1.93; P < .0 0 01). Conclusions: SARS-CoV-2 IgG antibodies and prior COVID-19 infection do not appear to offer meaningful protection against COVID-19 recurrence in healthcare workers. Recurrence would impact decisions regarding ongoing healthcare resource utilization. This study can inform considerations for vaccine administration to vulnerable groups. (c) 2021 Elsevier Inc. All rights reserved.