Using a cutoff of 0.2 for a low CD4 response and 0.05 for a low CD8 response at the Post V1 visit, we found that 9 of 12 (75%) patients with autoimmune diseases with a breakthrough infection prior to boosting manifested low T cell responses at the Post V1 visit, compared with 90 of 228 (39%) of patients without breakthrough infections (P < 0.02). The gene discussed is CD4; the disease is autoimmune disease.