This study investigated the infectivity of severe acute respiratory syndrome (SARS-CoV-2) in individuals who re-tested positive for SARS-CoV-2 RNA after recovering from their primary illness. We investigated 295 individuals with re-positive SARS-CoV-2 polymerase chain reaction (PCR) test results and 836 of their close contacts. We attempted virus isolation in individuals with re-positive SARS-CoV-2 PCR test results using cell culture and confirmed the presence of neutralizing antibodies using serological tests. Viral culture was negative in all 108 individuals with re-positive SARS-CoV-2 PCR test results in whom viral culture was performed. Three new cases of SARS-CoV-2 infection were identified among household contacts using PCR. Two of the three new cases had had contact with the index patient during their primary illness, and all three had antibody evidence of past infection. Thus, there was no laboratory evidence of viral shedding and no epidemiological evidence of transmission among individuals with re-positive SARS-CoV-2 PCR test results.

Due to the increased need for the efficient use of public funds and the importance of private investment, there have been many studies on the effects of these factors on corporate performance. However, few studies have been conducted based on an integrated perspective. In addition, most studies have investigated cases in leading countries and have rarely studied latecomer countries. Therefore, this study investigated the step-by-step effects of government support on firm performance (innovation performance, venture capital (hereafter VC) investment, and financial performance) based on the data on in vitro diagnostic (hereafter IVD) firms in Korea. In particular, we demonstrate the sequential effects of these variables with a time lag. The results of the panel regression analysis indicate that government R&D support improved the innovation performance of IVD firms, but this increased innovation performance did not attract VC investment. Meanwhile, VC investment has a positive impact on a firm’s financial performance. These findings have policy implications and suggest that government support plays a pivotal role in a company’s innovation performance, and thus continuous investment is required. However, innovation performance negatively affects short-term financial performance, and thus technology commercialization should be supported.

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