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. Author manuscript; available in PMC: 2014 May 1.
Published in final edited form as: Clin Immunol. 2013 Mar 15;147(2):79–88. doi: 10.1016/j.clim.2013.02.022

Figure 2. The ratios of pre/post vaccination IgG levels specific for influenza virus strains correlate with the changes in hemagglutinin inhibition (HI) antibody titers in young but not elderly people after influenza vaccination.

Figure 2

(A–B) Serum levels of IgG specific for individual strains of influenza virus included in influenza vaccine 2011–2012 (A/California/7/2009 (H1N1), A/Perth/16/2009 (H3N2) and B/Brisbane/60/2008) were measured in young (n = 29) and elderly (n = 26) adults by ELISA before and ~32 days (range, 29–36 days) after influenza vaccination. Serum HI antibody titers for the same strains of influenza virus were measured by HI assay. (AB) Ratios of Pre/post vaccination IgG levels specific for individual influenza viral strains were correlated with the changes in HI antibody titers in young and elderly people. P values were determined by Pearson correlation analysis.