After vaccination, SARS-CoV-2–specific saliva IgA levels, normalized with respect to total IgA levels, were significantly higher in participants with previous infection, as compared with the most responsive mRNA-1273 (Moderna) recipients (median normalized levels, 155 × 10−5 vs 37 × 10−5 at day 29; 107 × 10−5 vs 54 × 10−5 at day 57; and 104 × 10−5 vs 70 × 10−5 at day 180 [P < .001]). The gene discussed is CD79A; the disease is infection.