METHODS: We recruited a cohort of 23 healthcare workers who received their bivalent Omicron BA.1 / ancestral mRNA booster vaccination or were infected with the Omicron variant at a median of 144 days and 227 days before blood collection, respectively. In this cohort, we compared the performances of two widely utilized commercial SARS-CoV-2 interferon-gamma release assays (IGRAs), i.e., QuantiFERON SARS-CoV-2 and T-SPOT.COVID, and an in-house designed Omicron enzyme-linked immunospot (ELISpot).
RESULTS: The QuantiFERON SARS-CoV-2 and T-SPOT.COVID assays detected SARS-CoV-2 spike-specific T cells in 34.8 % and 21.7 % of participants, respectively. Moreover, our in-house designed ELISpot that included Omicron BA.4 and BA.5 full-spike peptides detected T cell responses in 47.8 % of participants and was strongly associated with the T-SPOT.COVID.
CONCLUSIONS: The evaluation of SARS-CoV-2 T cell immunity using commercially accessible assays may yield disparate outcomes as results from different assays are not directly comparable. A specific Omicron ELISpot should be considered to assess Omicron-specific T cell immunity.
方法:我们招募了一组23名医护人员,他们在采血前144天和227天的中位数接受了二价OmicronBA.1/祖先mRNA加强疫苗接种或感染了Omicron变体,分别。在这个队列中,我们比较了两种广泛使用的商业SARS-CoV-2干扰素-γ释放试验(IGRAs)的性能,即,QuantiferonSARS-CoV-2和T-SPOT。COVID,和内部设计的Omicron酶联免疫斑点(ELISpot)。
结果:QuantiferonSARS-CoV-2和T-SPOT。COVID检测在34.8%和21.7%的参与者中检测到SARS-CoV-2尖峰特异性T细胞,分别。此外,我们内部设计的ELISpot包括OmicronBA4和BA.5全峰肽,在47.8%的参与者中检测到T细胞应答,并且与T-SPOT密切相关.COVID.
结论:使用商业上可获得的测定法评估SARS-CoV-2T细胞免疫可能会产生不同的结果,因为不同测定法的结果无法直接比较。应考虑使用特定的OmicronELISpot来评估Omicron特异性T细胞免疫。