key: cord-284464-avriske3
authors: Liu, Tao; Wu, Sanyun; Zeng, Guang; Zhou, Fuling; Li, Yirong; Guo, Fangjian; Wang, Xinghuan
title: Recurrent positive SARS‐CoV‐2: Immune certificate may not be valid
date: 2020-06-09
journal: J Med Virol
DOI: 10.1002/jmv.26074
sha: 
doc_id: 284464
cord_uid: avriske3

Currently, coronavirus disease in 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)1 has become a global pandemic. The presence of SARS-CoV-2 in COVID-19 patients is usually confirmed using real-time reverse-transcriptase polymerase chain reaction (RT-PCR) method.2 This article is protected by copyright. All rights reserved.

median and interquartile range and differences were compared using Mann-Whitney test. Categorical variables were described as frequency rates and percentages. The χ 2 test was used for the comparison of categorical variables and Fisher's exact test was used when frequency was too low. Statistical analyses were conducted using SAS software version 9.4 (SAS Institute; Carey, NC). A two-sided P < .05 was considered statistically significant.

Among 150 patients who were recovering from COVID-19, 11 (7.3%, 95% confidence interval: 3.1%-11.6%) tested positive again for SARS-CoV-2 in throat swabs. Positive rates for SARS-CoV-2 did not differ by sex or age. Characteristics were similar between those positive and those not ( Table 1 ). There were no differences in the prevalence of IgM or IgG to SARS-CoV-2 ( Figure S1 ) or serum levels of these antibodies (Table 1) 

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