Fig. 2.

Baseline nasal immunoglobulin (Ig)A does not impact antibody response to vaccine. Nasal and oral swabs were collected prior to live attenuated influenza vaccine (LAIV) immunization. (a) Influenza strain‐specific IgA was measured in nasal swabs. (b) Influenza strain‐specific IgG was measured in oral swabs. Fold change in IgG specific for H1 (c) and H3 (d) were compared with baseline IgA. Points represent individuals; numbers above IgA are individuals with detectable IgA. *P < 0·05, *** =P < 0·001.