Comparison of GMC (geometric mean concentration) ELISA, IgG, µg/mL (dichotomous analysis) between oldest age group (Age ≥75 yrs, n = 86) and other (Age <75 yrs, n = 226).

For 23vPPV group, both younger and older increased substantially post vaccine for all serotypes and at least 2 fold rise except for 6A – not in 23vPPV- which increased by 1.8 and 1.25 for <75 yrs and ≥75 yrs respectively. Types 14 and 18C showed greatest increment of 5.9 and 7.6 fold respectively for <75 yrs but fold increase was sig less for ≥75 yrs of 2.6 and 3.6 respectively.

For PCV7 group, also lower responses among ≥75 yrs for 7v types except 4 (also 23vPPV) which was particularly marked for 19F and 23F where there was not sig difference by age for 23v. Notably, GMCs among ≥75 yrs group were not higher 6 months post PCV7 compared with 23vPPV – in fact v similar 4 (0.95 vs 1.23), 6B (2.85 vs 2.78), 9V (2.11 vs 2.89), 14 (6.37 vs 6.41) 18C (3.39 vs 4.30), 19F (2.26 vs 1.68) and 23F (2.61 vs 2.17) – note 9V difference sig for overall group with ratio of 1.40 and this ratio is same for ≥75 yrs - 1.4. For other non 7v types, there are related types (6A and 19A) and one non 7v type (3). Sig ratio for 3, marginal sig (0.08) for 19A and non sig for 6A. Lower responses among ≥75 yrs for all serotypes for both vaccines types.