Characteristics of SARS-CoV-2 Reinfection

Study Overview
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Brief Summary
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As the COVID-19 pandemic continues and the number of individuals with previous infection rises, numbers of SARS-CoV-2 reinfection are increasing. The second Omicron wave in Shanghai, China caused by BA.5-sublineages led to a large fraction of reinfections among BA.2 primary infections. To better understand the SARS-CoV-2 reinfection rate and clinical severity of reinfections, the investigators conducted a multi-centre cohort study. The investigators hope to provide valuable clinical evidences for reinfections and offer guidance for future policy making.

Detailed Description
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The investigators used data from Huashan Hospital, Renji Hospital, and Shanghai Jing' an Central Hospital to collect information on SARS-CoV-2 primary infections with BA.2 during 1 March to 23 May 2022, and followed up for participants' reinfections with BA.5-lineages during 1 December 2022 to 14 January 2023. After matched 1:1 by age and gender with the reinfection cohort, data of primary infections with BA.5-sublineages were also collected. Reinfection cases were defined as having positive COVID-19 PCR or antigen test, at least 90 days after participants' first positive testing. Basic information, vaccination status, time interval between two infections, and clinical manifestations were collected.

Official Title
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Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China;

Conditions
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COVID-19

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All PCR- or RAT-confirmed SARS-CoV-2 reinfections were included in the study. Exclusion Criteria: Patients who did not know if they were reinfected were excluded.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Primary infections during March-May 2022<br>Hospitalized COVID-19 patients infected with BA·2 during 1 March to 23 May 2022 from Huashan Hospital, Renji Hospital, and Shanghai Jing' an Central Hospital. | |
| Primary infections during December 2022-January 2023<br>Primary infections with BA.5-sublineages during 1 December 2022 to 14 January 2023, matched 1:1 by age and sex with reinfections during the same period. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Characteristics of all enrolled SARS-CoV-2 patients during two periods. | Basic information, vaccination status, time interval between two infections, and clinical manifestations | 2022-12 2023-2 | 
| Characteristics and multivariate analysis of risk factors for SARS-CoV-2 reinfection by gender, age, vaccination status, clinical severity and Ct values of primary infection. | Sex, age, vaccination status, clinical severity of primary infection, and Ct values during primary infection | 2022-12 2023-2 | 
| Clinical characteristics of SARS-CoV-2 primary infection and reinfection among patients with reinfection in Shanghai | Fever, fatigue, sore throat, cough, anosmia and/or ageusia, muscle and/or joint pain, headache, chest congestion, diarrhea, runny nose, sleeping disorders, and pneumonia | 2022-12 2023-2 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Reinfection, risk factor, clinical severity