COVID-19 is caused by SARS-CoV-2 infection and leads from asymptomatic to severe outcomes. The recurrence of the COVID-19 has been described, however, mechanisms involved remains unclear. Thus, the work aimed to investigate the role of multifunctional T cells in patients with recurrent COVID-19. We evaluated clinical characteristics, presence of anti-S1 and anti-Nucleocapsid IgG in patients’ sera, and multifunctional T cells (for IFN-γ, IL-2, and TNF-α) in patients with multiple episodes of COVID-19 and controls. Data demonstrate that patients with recurrent COVID-19 have a T cell pattern predominantly related to IFN-γ production. Also, patients with COVID-19 history and absence of anti-S1 IgG had lower levels of CD4+ IFN + IL-2 + TNF + T cells independently of number of disease episodes. Complementary, vaccination changed the patterns of T cells phenotypes and induced IgG seroconversion, despite not induce higher levels of multifunctional T cells in all patients. In conclusion, the data suggest that recurrent disease is related to early-disease T cell profile and absence of anti-S1 IgG is related to lower multifunctional CD4 T cell response, what suggests possibility of new episodes of COVID-19 in these patients.

COVID-19 是由 SARS-CoV-2 感染引起的，可导致无症状到严重后果。已经描述了 COVID-19 的复发，但所涉及的机制仍不清楚。因此，这项工作旨在研究多功能 T 细胞在复发性 COVID-19 患者中的作用。我们评估了多次 COVID-19 发作患者和对照患者的临床特征、患者血清中抗 S1 和抗核衣壳 IgG 的存在以及多功能 T 细胞（IFN-γ、IL-2 和 TNF-α） 。数据表明，复发性 COVID-19 患者的 T 细胞模式主要与 IFN-γ 的产生相关。此外，有 COVID-19 病史且缺乏抗 S1 IgG 的患者的 CD4+ IFN + IL-2 + TNF + T 细胞水平较低，与疾病发作次数无关。作为补充，疫苗接种改变了 T 细胞表型的模式并诱导 IgG 血清转化，尽管并未在所有患者中诱导更高水平的多功能 T 细胞。总之，数据表明，疾病复发与早期疾病 T 细胞谱有关，抗 S1 IgG 的缺失与多功能 CD4 T 细胞反应较低有关，这表明这些患者可能出现新的 COVID-19 发作。