At 4–6 weeks post BA.1/BA.2 infection, 75.0%–83.3% of participants (depending on the T‐cell functional subset) had detectable heterologous CD4+ T‐cell responses directed to this contemporary subvariant (Figure 2A); 9/12 (75.0%) of participants had detectable JN.1‐responsive polyfunctional CD4+ T‐cells, and 10/12 (83.3%) had JN.1‐responsive IL‐2 monofunctional CD4+ T‐cells. The gene discussed is CD4; the disease is infection.