In individuals without prior infection, compared with day 1, increases of specific salivary IgA levels were substantially smaller, particularly after BNT162b2 vaccination, reaching statistical significance only at day 57 (36 × 10−5 [IQR, 19 × 10−5 to 79 × 10−5] vs 49 × 10−5 [IQR, 25 × 10−5 to 103 × 10−5]; P = .01) (Figure 3). Here, CD79A is linked to infection.