IFNA1 and toxic epidermal necrolysis: However, others contend that the pathophysiology of post‐COVID‐19 vaccine TEN/SJS lies in the activation of type 1 helper T‐cells (Th1s), which released cytokines such as TNF‐ɑ and IFN‐ɣ that subsequently activate cytotoxic CD8+ T‐cells responsible for triggering keratinocyte apoptosis.11, 13