Supplementary Materials Fig. immunization. There is a significant increase in nasal immunoglobulin (Ig)A to the H3N2, B/Victoria lineage (B/Brisbane) and B/Yamagata lineage (B/Phuket) components, but not to the H1N1 component. The fold change in nasal IgA response was inversely proportional to the baseline nasal IgA titre for H1N1, H3N2 and B/Brisbane. We investigated possible associations that may explain baseline nasal IgA, including age and prior vaccination status, but found different patterns for different antigens, suggesting that the response is multi\factorial. Overall, we observed differences in immune responses to different viral strains included in the vaccine; the reasons for this require further investigation. analysis was performed to investigate correlations between age, vaccination status and baseline nasal IgA. For analyses comparing strains, correction was designed for six multiple evaluations as Mouse monoclonal to CD31 well as for analyses looking at pre\ and post\amounts for four multiple evaluations. Evaluation was performed in Stata edition 15 and GraphPad Prism edition 8. Results Posting swabs does not impact influenza specific nasal IgA recovery We undertook a pilot test to confirm that posting of samples (resulting in a 3\day delay in processing) had no effect on the recovery of?influenza\specific nasal IgA in six adult volunteers. There were no significant differences in antibody levels measured in the fresh or posted samples to either the H1N1 (paired analysis to LY 2183240 evaluate the factors that might cause these differences. One possibility is usually that pre\existing immunity may reduce vaccine response. We investigated whether there was a link between baseline nasal IgA and fold change in nasal IgA after immunization. There was a poor but significant unfavorable relationship between baseline nasal IgA and fold\change in response for H1N1, H3N2 and B/Bris (Fig. ?(Fig.2).2). As baseline nasal IgA response may reflect the history of computer virus exposure which is dependent on age, we compared the age of the child at immunization with the baseline nasal IgA (Fig. ?(Fig.3).3). We LY 2183240 found a significant, but again very weak, correlation between age and baseline nasal IgA for H3N2 (Fig. ?(Fig.3b)3b) and B/Bris (Fig. ?(Fig.3c),3c), but LY 2183240 no correlation for nasal IgA responses to H1N1 (Fig. ?(Fig.3a)3a) or B/Phu (Fig. ?(Fig.33d). Open in a separate window Physique 2 Relationship between baseline nasal immunoglobulin (Ig)A titre and fold change in nasal IgA response. Nasal IgA titre at baseline was compared to the fold change in response to H1N1 (a), H3N2 (b), B/Bris (c) and B/Phu (d) antigens. Open in a separate window Physique 3 Relationship between age and baseline nasal immunoglobulin (Ig)A. Age was compared to the nasal IgA titre at baseline to H1N1 (a), H3N2 (b), B/Bris (c) and B/Phu (d) antigens for all those children. We also investigated whether previous influenza vaccination affected nasal IgA. The children were grouped by whether or not they previously had received influenza vaccination. Two of the strains in this study have been previously included in LAIV: A/California/7/2009 pdm\like and B/Brisbane/60/2008, and two of the strains were newly included in the 2015C16 vaccine formulation: A/Switzerland/9715293/2013 and B/Phuket/3073/2013. There was no difference in the baseline nasal IgA LY 2183240 titres to any of the vaccine strains when comparing vaccine\naive children and previously vaccinated children (Fig. ?(Fig.4a).4a). We did not identify a difference in baseline nasal IgA titres in LY 2183240 children who had previously received LAIV compared to IIV (Fig. ?(Fig.4b).4b). There was no significant difference in fold\change of nasal IgA when children were grouped by previous vaccination history (Fig. ?(Fig.44c). Open in a separate window Physique 4 Impact of influenza vaccination history on nasal immunoglobulin (Ig)A. Children grouped by prior vaccination position, vaccinated (shut icons) or no prior vaccine (open up.