{"title":"Enhanced immunogenicity of SARS-CoV-2 antigen with aluminum adjuvant and polysaccharide nucleic acid fraction of Bacillus Calmette Guerin.","authors":"Jia Ji, Miaojin Zhu, Linwei Zhu, Zhiyong Liu, Shengmei Yang, Taoming Tang, Zhigang Wu, Danrong Shi, Jiale Zhang, Xiaodi Zhang, Hangping Yao","doi":"10.1016/j.ijantimicag.2025.107578","DOIUrl":null,"url":null,"abstract":"<p><p>Vaccine immunization strategies are crucial for eliciting vaccine-induced immune responses, particularly in immune compromised populations and older adults. In clinical practice in China, the polysaccharide nucleic acid fraction of Bacillus Calmette-Guérin (BCG-PSN) is extensively used as an immune modulatory agent. Herein, we describe a new immunization strategy using the SARS-CoV-2 antigen (original strain) with aluminum adjuvant and BCG-PSN. We evaluated whether BCG-PSN enhances humoral and cellular immune responses to the SARS-CoV-2 vaccine in K18-hACE2 and BALB/c mice by assessing antibody and germinal center (GC) responses, as well as the quantity and functionality of memory T cells in the spleen. At day 28 after the first immunization, the SARS-CoV-2 antigen with Alum, when combined with BCG-PSN, significantly elevated the levels of IgGantibodies. It significantly enhanced the spleen's GC structure, amplified the SARS-CoV-2 antigen-specific T cell response, and conferred protection to mice against the Delta variant challenge. This study provides a reference to evaluate immunization strategies for vaccines with high immunological efficacy, and the SARS-CoV-2 antigen combined with Alum and BCG-PSN enhances immunogenicity by significantly boosting cellular immune responses after vaccine administration. The study focuses on the impact of BCG-PSN on the SARS-CoV-2 antigen, examining its role in generating neutralizing antibodies (NAbs) and eliciting T cell responses.</p>","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":" ","pages":"107578"},"PeriodicalIF":4.6000,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Antimicrobial Agents","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.ijantimicag.2025.107578","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/7/22 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"INFECTIOUS DISEASES","Score":null,"Total":0}
引用次数: 0
Abstract
Vaccine immunization strategies are crucial for eliciting vaccine-induced immune responses, particularly in immune compromised populations and older adults. In clinical practice in China, the polysaccharide nucleic acid fraction of Bacillus Calmette-Guérin (BCG-PSN) is extensively used as an immune modulatory agent. Herein, we describe a new immunization strategy using the SARS-CoV-2 antigen (original strain) with aluminum adjuvant and BCG-PSN. We evaluated whether BCG-PSN enhances humoral and cellular immune responses to the SARS-CoV-2 vaccine in K18-hACE2 and BALB/c mice by assessing antibody and germinal center (GC) responses, as well as the quantity and functionality of memory T cells in the spleen. At day 28 after the first immunization, the SARS-CoV-2 antigen with Alum, when combined with BCG-PSN, significantly elevated the levels of IgGantibodies. It significantly enhanced the spleen's GC structure, amplified the SARS-CoV-2 antigen-specific T cell response, and conferred protection to mice against the Delta variant challenge. This study provides a reference to evaluate immunization strategies for vaccines with high immunological efficacy, and the SARS-CoV-2 antigen combined with Alum and BCG-PSN enhances immunogenicity by significantly boosting cellular immune responses after vaccine administration. The study focuses on the impact of BCG-PSN on the SARS-CoV-2 antigen, examining its role in generating neutralizing antibodies (NAbs) and eliciting T cell responses.
期刊介绍:
The International Journal of Antimicrobial Agents is a peer-reviewed publication offering comprehensive and current reference information on the physical, pharmacological, in vitro, and clinical properties of individual antimicrobial agents, covering antiviral, antiparasitic, antibacterial, and antifungal agents. The journal not only communicates new trends and developments through authoritative review articles but also addresses the critical issue of antimicrobial resistance, both in hospital and community settings. Published content includes solicited reviews by leading experts and high-quality original research papers in the specified fields.