Covid Reinfection versus Asymptomatic Carrier State: A Case Report

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first discovered in China in December 2019, has been implicated in the current coronavirus disease 2019 (COVID-19) pandemic. Although much has been learned about the virus which peaked with the development of the vaccine, there is still a lot of unanswered questions. Maximum duration of positive SARS-CoV-2 real-time reverse transcriptase polymerase chain reaction (RT-PCR) from symptom onset may be up to 3 months [1], however it is not known if the continued detection of the viral genome implies prolonged infectivity or presence of a non-viable virus [2]. Most people with COVID-19 develop antibodies after resolution of acute infection [2]. The exact duration of these antibodies in the body is unknown, but some studies have shown that both memory T-cells and B-cells can persist up to 6 to 8 months after acute SARS-CoV-2 infection [3]. These SARS-CoV-2 antibodies may confer some immunity to the person after the acute infection and have been associated with protection against subsequent infection in nonhuman primates by the same viral strain during the early recovery phase [4]. In humans, however, it is unknown to what extent this immune response indicates a protective immunity to subsequent infection with SARS-CoV-2 [5]. Few cases of reinfection have been documented worldwide with varying symptom severity; the first case in the US was published in January 2021 (reinfection occurred in June 2020) [5]. None of the initial cases reported the presence of SARS-CoV-2 antibodies at the time of reinfection. We present a patient who tested positive to SARS-CoV-2 RT-PCR twice in 10 months (Table 1). At both times, she was asymptomatic and the second time, she had coexisting SARS-CoV-2 antibodies.