Evidence map›Paper›PMID 40751140›Full record

ArticleBMC infectious diseases2025

Clinical and immunological insights into SARS-CoV-2 reinfection: a propensity score-matched cohort study.

Chenxi Zhao, Lu Liu, Ziruo Ge, Jingxia Wang, Ranran Wang, Zhouling Jiang, Di Tian, Zhihai Chen

Abstract read
In one paragraph

Article in BMC infectious diseases, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

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0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

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PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Chenxi Zhao *National Key Laboratory of Intelligent Tracking and Forecasting for infectious Diseases, Beijing Ditan Hospital, Capital Medical University, No. 8 Jingshun East Street, Chaoyang District, Beijing, 100015, China.
Lu Liu *National Key Laboratory of Intelligent Tracking and Forecasting for infectious Diseases, Beijing Ditan Hospital, Capital Medical University, No. 8 Jingshun East Street, Chaoyang District, Beijing, 100015, China.
Ziruo Ge *National Key Laboratory of Intelligent Tracking and Forecasting for infectious Diseases, Beijing Ditan Hospital, Capital Medical University, No. 8 Jingshun East Street, Chaoyang District, Beijing, 100015, China.
Jingxia WangNational Key Laboratory of Intelligent Tracking and Forecasting for infectious Diseases, Beijing Ditan Hospital, Capital Medical University, No. 8 Jingshun East Street, Chaoyang District, Beijing, 100015, China.
Ranran WangNational Key Laboratory of Intelligent Tracking and Forecasting for infectious Diseases, Beijing Ditan Hospital, Capital Medical University, No. 8 Jingshun East Street, Chaoyang District, Beijing, 100015, China.
Zhouling JiangNational Key Laboratory of Intelligent Tracking and Forecasting for infectious Diseases, Beijing Ditan Hospital, Capital Medical University, No. 8 Jingshun East Street, Chaoyang District, Beijing, 100015, China.
Di TianNational Key Laboratory of Intelligent Tracking and Forecasting for infectious Diseases, Beijing Ditan Hospital, Capital Medical University, No. 8 Jingshun East Street, Chaoyang District, Beijing, 100015, China. tiandi412@hotmail.com.
Zhihai ChenNational Key Laboratory of Intelligent Tracking and Forecasting for infectious Diseases, Beijing Ditan Hospital, Capital Medical University, No. 8 Jingshun East Street, Chaoyang District, Beijing, 100015, China. chenzhihai0001@126.com.

Funding

Beijing Research Center for Respiratory Infectious Diseases Project BJRID2024-009National Key Research and Development Program of China 2022YFF1203201
6 · The paper itself

Abstract

backgroundThe global circulation of SARS-CoV-2 has led to an increasing number of reinfections, raising concerns about their clinical and immune consequences. Understanding the differences in disease severity, vaccination impact, and immune response between primary infections and reinfections is essential for guiding public health strategies.

methodsWe conducted a retrospective cohort study of hospitalized COVID-19 patients at Beijing Ditan Hospital from January 2023 to June 2024. SARS-CoV-2 reinfection cases were matched 1:2 with primary infection cases using nearest neighbor propensity score matching (PSM) to balance age, sex, and comorbidities between the groups. Clinical characteristics, laboratory findings, serum antibody levels, lymphocyte subsets, and the impact of vaccination on disease severity were analyzed.

resultsA total of 907 patients were included, comprising 821 with primary infection and 86 with reinfection. After matching, 131 cases remained in the primary infection group and 75 in the reinfection group. No significant differences were observed in disease severity, mortality, or most clinical symptoms. Trend analysis revealed that an increasing number of vaccine doses was significantly associated with a decreasing trend in severe disease in both the primary infection group (P = 0.0221) and the reinfection group (P = 0.0449). IgG levels were significantly higher in reinfected patients (P < 0.001), whereas IgM levels showed no significant difference (P = 0.474). Among patients with primary infection, severe cases exhibited lower T cell counts than non-severe cases (P < 0.001), but no significant differences in T cell subsets were observed between non-severe and severe reinfections.

conclusionsThe higher IgG levels in reinfected individuals suggest a robust immune memory response, while T cell depletion plays a crucial role in severe primary infections. Vaccination provided a protective effect against severe disease in both primary and reinfected individuals, with a significant decreasing trend in severe/critical cases as the number of vaccine doses increased.

Indexed as

COVID-19ReinfectionSARS-CoV-2AdultAgedAntibodies, ViralCohort StudiesCOVID-19 VaccinesFemaleHumansImmunoglobulin GMaleMiddle AgedPropensity ScoreRetrospective StudiesSeverity of Illness IndexAntibodies, ViralCOVID-19 VaccinesImmunoglobulin GCOVID-19Propensity score matchingReinfection

Identifiers

PMID40751140
PMCPMC12315331

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.