Figure 3.

(A) Anti–hemagglutination immunoglobulin G (HA) geometric mean titer ratio (GMTR) and (B) prevaccination and postvaccination geometric mean HA titers in the 90 substudy patients

A, The prevaccination and postvaccination GMTR of HA antibodies by vaccine strain are presented. Mean group-level change in titer prevaccination to postvaccination of greater than 2.5 is the benchmark used by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA).12,13 B, The geometric mean and coefficient of variation (CV) for each strain before and after vaccination are presented. These values were used to calculate the GMTR. A/H1N1, A/California/7/2009; A/H3N2, A/Texas/50/2012; B, B/Massachusetts/2/2012.