In the trial of Sahin et al., RBD-specific CD4+ and CD8+ T cells produced IFN-γ, IL-2, or both, but they did not produce IL-4 in the majority of 52 participants, with only one single individual developing a significant IL-4 secretion following BNT162b1 vaccine, indicating the unlikely pathogenic role of a potentially deleterious TH2 responses accounting for vaccine-induced pemphigus [11]. Here, IL4 is linked to pemphigus.