Fig. 2.

Mucosal and serum antibody responses in subjects with previous infection compared to vaccinated only. (a and b) Anti-triS IgA (log₁₀ ng/mL) measured in NLF (a) and serum (b) of vaccinated with 2 or 3 doses, or convalescent. (c) Anti-triS s-IgA (log₁₀ AU/mL) antibody titers in NLF of vaccinated with 2 or 3 doses, or convalescent. (d and e) Anti-triS IgG (log₁₀ ng/mL) measured in NLF (d) and serum (e) of vaccinated with 2 or 3 doses, or convalescent. A generalized linear model was used to determine differences of means, p values are shown above brackets. The mean + 3SD of 11 negative samples was used to set a cut-off for anti-triS IgA, s-IgA and IgG in NLF. The mean + 3SD of 56 pre-pandemic serum samples was used to set a cut-off for anti-triS IgA in serum samples. The mean + 3SD of 48 pre-pandemic serum samples was used to set a cut-off for anti-triS IgG in serum samples.