Acknowledgements
The authors would like to thank the members of the Duke Molecular and Epidemiological Study of Suspected Infection (MESSI) clinical team for their support in enrollment and sampling. Viral load assays were run by Pooja Chaudhary in the Duke RBL Virology unit under the management of Dr. Thomas Oguin.
Corresponding Author :
Justine M. McKittrick
Duke University School of Medicine
Durham, NC 27710
email Justine.mckittrick@duke.edu
phone: 919-684-8111
Abstract Purpose : Several cases of symptomatic reinfection with SARS-CoV-2 after full recovery from a prior episode have been reported. While an uncommon phenomenon, an improved understanding of the risk factors for reinfection and the character and duration of the serological responses to infection and vaccination is critical for managing the COVID-19 pandemic.
Methods :  We described four cases of SARS CoV-2 reinfection in individuals representing a spectrum of healthy and immunocompromised states, including 1) a healthy 41-year-old pediatrician, 2) an immunocompromised 31-year-old with granulomatosis with polyangiitis, 3) a healthy 26-year-old pregnant woman, and 4) a 50-year-old with hypertension and hyperlipidemia. We performed confirmatory quantitative RT-PCR and qualitative IgM and quantitative IgG testing on all available patient samples to confirm the presence of infection and serological response to infection.
Results : Our analysis showed that patients 1 and 2, a healthy and an immunocompromised patient, both failed to mount a robust serologic response to initial infection. In contrast, patient 3 and 4, with minimal comorbid disease, both mounted a strong serological response to their initial infection but were still susceptible to reinfection.
Conclusion : Repeat episodes of COVID-19 seem capable of occurring to patients regardless of the presence of known risk factors for infection or level of serological response to infection, although this did not trigger critical illness in any instance.
The COVID-19 pandemic has resulted in over 100 million cases and 2 million deaths worldwide [1]. While prior infection with SARS-CoV-2 has been shown to be highly protective against reinfection [2,3], reports have surfaced over the course of the pandemic about cases of patients who have re-tested positive for SARS-CoV-2 infection after resolution of symptoms and viral shedding from their initial episode [4-12]. Our understanding of the immune mechanisms which define protection and the reason certain patients are more susceptible to reinfection than others remains incomplete. Gathering more data about these rare cases may help further our comprehension of reinfection and immunity and is essential to optimizing management of the COVID-19 crisis. The following report details four cases of SARS-Co-V-2 reinfection in patients with different medical backgrounds.