Figure 1. Longitudinal Evolution of Serum and Salivary Anti–Spike IgG and IgA Following Messenger RNA (mRNA) Vaccination in Individuals With or Without Previous Exposure to SARS-CoV-2.

Evolution over time in individuals with previous SARS-CoV-2 infection receiving the BNT162b2 (Pfizer-BioNTech) vaccine, SARS-CoV-2–naive individuals receiving the mRNA-1273 (Moderna) vaccine, and SARS-CoV-2–naive individuals receiving BNT162b2 (Pfizer-BioNTech) of median log₁₀ levels of salivary and serum anti–spike IgG or IgA at days 1, 29, 57, and 180 after vaccination. Error bars indicate 95% CI. Dotted lines indicate threshold values computed as mean plus 1 SD of measurements made at day 1 among patients without prior infection. Results of comparison between groups at each time (Wilcoxon rank sum test) are shown.

^aP ≤ .001, previous infection vs infection naive with mRNA-1273 vaccine.

^bP ≤ .001, previous infection vs infection naive with BNT162b2 vaccine.

^cP ≤ .001, infection naive with mRNA-1273 vaccine vs infection naive with BNT162b2 vaccine.