Table 1.

Geometric Mean Titers (GMTs) of anti-NA antibodies in both age groups against A(H1N1) and A(H1N1) pdm09 strains. Comparison between GMTs of the adult and elderly groups. (CI: confidence intervals).

A(H1N1) and A(H1N1) pdm09 Strains	Anti-NA GMTs (CI 95%)		p-Value
	Adults (15–64 Years)	Elderly (≥65 Years)
A/PR/8/1934	106.5 (81.2–137.7)	166.6 (131.1–209.9)	0.016
A/Weiss/1943	369.6 (269.9–485.7)	716.0 (534.0–974.7)	0.002
A/FM/1/1947	169.5 (128.3–215.5)	351.9 (283.9–434.4)	<0.001
A/Brazil/11/1978	448.5 (364.5–542.9)	269.0 (211.8–336.1)	0.001
A/Brisbane/59/2007	222.3 (179.5–276.4)	251.0 (211.4–296.5)	0.399
A/California/07/2009	100.2 (79.3–127.7)	136.9 (109.2–170.9)	0.066