Serviço de Patologia Clínica, Centro Hospitalar Universitário de São João, Porto, Portugal.
EPIUnit-Instituto de Saúde Pública, Universidade do Porto, Porto, Portugal.
PLoS One. 2024 May 10;19(5):e0303244. doi: 10.1371/journal.pone.0303244. eCollection 2024.
To predict protective immunity to SARS-CoV-2, cellular immunity seems to be more sensitive than humoral immunity. Through an Interferon-Gamma (IFN-γ) Release Assay (IGRA), we show that, despite a marked decrease in total antibodies, 94.3% of 123 healthcare workers have a positive cellular response 6 months after inoculation with the 2nd dose of BNT162b2 vaccine. Despite the qualitative relationship found, we did not observe a quantitative correlation between IFN-γ and IgG levels against SARS-CoV-2. Using stimulated whole blood from a subset of participants, we confirmed the specific T-cell response to SARS-CoV-2 by dosing elevated levels of the IL-6, IL-10 and TNF-α. Through a 20-month follow-up, we found that none of the infected participants had severe COVID-19 and that the first positive cases were only 12 months after the 2nd dose inoculation. Future studies are needed to understand if IGRA-SARS-CoV-2 can be a powerful diagnostic tool to predict future COVID-19 severe disease, guiding vaccination policies.
为了预测对 SARS-CoV-2 的保护性免疫，细胞免疫似乎比体液免疫更敏感。通过干扰素-γ（IFN-γ）释放试验（IGRA），我们发现，尽管总抗体明显下降，但在接种 BNT162b2 疫苗第二剂后 6 个月，123 名医护人员中有 94.3%仍保持阳性的细胞反应。尽管发现了定性关系，但我们没有观察到 IFN-γ与针对 SARS-CoV-2 的 IgG 水平之间的定量相关性。使用部分参与者的刺激全血，我们通过测定升高的 IL-6、IL-10 和 TNF-α 水平，证实了针对 SARS-CoV-2 的特异性 T 细胞反应。通过 20 个月的随访，我们发现没有感染的参与者患有严重的 COVID-19，并且首例阳性病例仅在接种第二剂后 12 个月出现。需要进一步的研究来了解 IGRA-SARS-CoV-2 是否可以成为预测未来 COVID-19 严重疾病的强大诊断工具，从而指导疫苗接种政策。
