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. 2024 May 30:12:1364048.
doi: 10.3389/fpubh.2024.1364048. eCollection 2024.

The serological IgG and neutralizing antibody of SARS-CoV-2 omicron variant reinfection in Jiangsu Province, China

Jinjin Chu #  1 , Qigang Dai #  1 , Chen Dong  1 , Xiaoxiao Kong  1 , Hua Tian  1 , Chuchu Li  1 , Jiefu Peng  1 , Ke Xu  1 , Hao Ju  1 , Changjun Bao  1   2   3 , Jianli Hu  1   2   3 , Liguo Zhu  1   2   3   4
Affiliations

The serological IgG and neutralizing antibody of SARS-CoV-2 omicron variant reinfection in Jiangsu Province, China

Jinjin Chu et al. Front Public Health. .

Abstract

Background: It is important to figure out the immunity of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) reinfection to understand the response of humans to viruses. A serological survey for previously infected populations in Jiangsu Province was conducted to compare the antibody level of SARS-CoV-2 in reinfection by Omicron or not.

Methods: Reinfection with SARS-CoV-2 was defined as an individual being infected again after 90 days of the initial infection. Telephone surveys and face-to-face interviews were implemented to collect information. Experimental and control serum samples were collected from age-sex-matched reinfected and non-reinfected cases, respectively. IgG anti-S and neutralizing antibodies (Nab) concentrations were detected by the Magnetism Particulate Immunochemistry Luminescence Method (MCLIA). Antibody titers were log(2)-transformed and analyzed by a two-tailed Mann-Whitney U test. Subgroup analysis was conducted to explore the relationship between the strain type of primary infection, SARS-Cov-2 vaccination status, and antibody levels. Multivariate linear regression models were used to identify associations between reinfection with IgG and Nab levels.

Results: Six hundred thirty-one individuals were enrolled in this study, including 327 reinfected cases and 304 non-reinfected cases. The reinfection group had higher IgG (5.65 AU/mL vs. 5.22 AU/mL) and Nab (8.02 AU/mL vs. 7.25 AU/mL) levels compared to the non-reinfection group (p < 0.001). Particularly, individuals who had received SARS-CoV-2 vaccination or were initially infected with the Wild type and Delta variant showed a significant increase in antibody levels after reinfection. After adjusting demographic variables, vaccination status and the type of primary infection together, IgG and Nab levels in the reinfected group increased by log(2)-transformed 0.71 and 0.64 units, respectively (p < 0.001). This revealed that reinfection is an important factor that affects IgG and Nab levels in the population.

Conclusion: Reinfection with Omicron in individuals previously infected with SARS-CoV-2 enhances IgG and Nab immune responses.

Keywords: IgG; Nab; SARS-CoV-2; immunity; omicron variant; public health; reinfection.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Flow chart of enrollment of study subjects.
Figure 2
Figure 2
Percentage of patients with clinical symptoms to Omicron.
Figure 3
Figure 3
Comparison of SARS-CoV-2 serum antibodies between the reinfection group and non-reinfection. (A) Comparison of SARS-CoV-2 serum-IgG between the two groups. (B) Comparison of SARS-CoV-2 Nab between the two groups (***indicates p < 0.001).
Figure 4
Figure 4
Subgroup analysis based on the type of primary SARS-CoV-2 infection. (A) Comparison of SARS-CoV-2 serum-IgG between the two groups according to primary infection strain. (B) Comparison of SARS-CoV-2 Nab between the two groups according to primary infection strain (**indicates p < 0.05, ***indicates p < 0.001, ns indicates p > 0.05).
Figure 5
Figure 5
Subgroup analysis based on the SARS-CoV-2 vaccination status. (A) Comparison of SARS-CoV-2 serum-IgG between the two groups according to the SARS-Cov-2 vaccination status. (B) Comparison of SARS-CoV-2 Nab between the two groups according to the SARS-CoV-2 vaccination status (**indicates p < 0.05, ***indicates p < 0.001, ns indicates p > 0.05).
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References

    1. Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, et al. . China novel coronavirus I, research T. A novel coronavirus from patients with pneumonia in China, 2019. N Engl J Med. (2020) 382:727–33. doi: 10.1056/NEJMoa2001017 - DOI - PMC - PubMed
    1. WHO . Coronavirus (COVID-19) dashboard. (2022). Available at: https://covid19.who.int/ (Accessed July 13, 2022).
    1. Fu D, He G, Li H, Tan H, Ji X, Lin Z, et al. . Effectiveness of COVID-19 vaccination against SARS-CoV-2 omicron variant infection and symptoms - China, December 2022-February 2023. China CDC Wkly. (2023) 5:369–73. doi: 10.46234/ccdcw2023.070, PMID: - DOI - PMC - PubMed
    1. Nordström P, Ballin M, Nordström A. Risk of SARS-CoV-2 reinfection and COVID-19 hospitalisation in individuals with natural and hybrid immunity: a retrospective, total population cohort study in Sweden. Lancet Infect Dis. (2022) 22:781–90. doi: 10.1016/s1473-3099(22)00143-8, PMID: - DOI - PMC - PubMed
    1. Pilz S, Theiler-Schwetz V, Trummer C, Krause R, Ioannidis JPA. SARS-CoV-2 reinfections: overview of efficacy and duration of natural and hybrid immunity. Environ Res. (2022) 209:112911. doi: 10.1016/j.envres.2022.112911, PMID: - DOI - PMC - PubMed

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