{
  "abstract": "Assessing vaccine effectiveness and longevity through measurements of vaccine-induced serum antibodies, as well as memory B and T cells in circulating blood years after vaccination, serves as an indicator of protection and durability. Here, we build upon studies by assessing serum levels of SARS-CoV-2 spike (S) protein–specific immunoglobulins, as well as the status of S protein–specific immune memory in both vaccinated individuals and those with hybrid immunity. We aimed to determine whether the patterns of immune memory reported up to six months post-vaccination in the literature still remains two years after vaccine exposure. Both vaccination and hybrid immunity elicited durable and robust antigen-specific T- and B-cell responses, with memory subsets remaining detectable for up to two years post-exposure. Individuals with hybrid immunity showed greater expansion of central, effector memory, and effector T-cell subsets and produced more IFN-γ per cell upon antigenic stimulation, indicating superior functional quality of effector cells. Our B-cell analyses revealed that hybrid-immune individuals had a higher frequency of S-specific B cells that, upon expansion, differentiated more rapidly into plasmablasts and plasma cells, resulting in increased numbers of these subsets. In contrast, vaccinated individuals exhibited higher S1-specific IgG levels in both culture supernatants and serum. Given the limited number of independent donors, these findings provide an exploratory characterization of long-term vaccine- and hybrid-immunity responses in these populations. Taken together, our findings indicate that approximately two years after exposure, hybrid-immune individuals maintain robust cellular immune responses, while vaccinated individuals retain higher S1-specific IgG antibody responses.",
  "abstract_shown": true,
  "affiliations": [
    "Florida Atlantic University, Charles E. Schmidt College of Medicine, Department of Medicine, 777 Glades Road, PO Box 3091, Boca Raton, FL, 33431, USA",
    "Corresponding author."
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Czdari Lee"
    },
    {
      "affs": [
        0
      ],
      "name": "Imtisal Imran"
    },
    {
      "affs": [
        0
      ],
      "name": "Sara Thomas"
    },
    {
      "affs": [
        1
      ],
      "name": "Mahyar Nouri-Shirazi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8aa9h1vgx9t29.bib",
  "cited_by": 0,
  "doi": "10.1016/j.clicom.2026.100144",
  "fulltext_url": "http://www.sciencedirect.com/science/article/pii/S2772613426000314",
  "id": "8aa9h1vgx9t29",
  "issns": [
    "2772-6134"
  ],
  "landing_url": "https://doi.org/10.1016/j.clicom.2026.100144",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "lcc",
      "RC581-607"
    ],
    [
      "openalex",
      "2725|SARS-CoV-2 and COVID-19 Research"
    ]
  ],
  "openalex": "W7223172882",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-30",
  "publisher": "Elsevier",
  "ris": "https://research.draconitic.com/paper/8aa9h1vgx9t29.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T13:47:20Z",
      "native_id": "7d428ce133e542c28056f21debc20e5b",
      "source": "doaj",
      "url": "https://doi.org/10.1016/j.clicom.2026.100144"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "openalex:2725|SARS-CoV-2 and COVID-19 Research",
      "subfield": "infectious-disease"
    }
  ],
  "title": "Comparative analysis of SARS-CoV-2 immune memory in vaccinated and hybrid individuals two years post-exposure",
  "title_text": "Comparative analysis of SARS-CoV-2 immune memory in vaccinated and hybrid individuals two years post-exposure",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T13:47:20Z",
  "url": "https://research.draconitic.com/paper/8aa9h1vgx9t29",
  "venue": "Clinical Immunology Communications",
  "versions": []
}