Differently from what observed after influenza vaccination [29], in CVID patients, Spike-specific T-cells producing IFN-ɣ did not increase (from T0: median 0 SFU (IQR 0–9) to T1: median 7 SFU (IQR 0–35), P = 0.151) and were significantly lower than in HD (P = 0.0001). Here, IFNA1 is linked to common variable immunodeficiency.