Difference in immune response in vaccinated and unvaccinated Swedish individuals after the 2009 influenza pandemic

Table 1 Mean values of A/H1N1/California/7/2009-specific Abs (measured by SRH) and IFN-γ production (in whole-blood assay) before (A) and after (C) the 2009–2010 flu season, in blood from study participants with our without seasonal flu vaccination (2006–2009)

Time point	A		C		A	C
	2006-2009 seasonal flu vacc.
	Vacc.	Not vacc.	Vacc.	Not vacc.	V/NV^1x-diff.
	SRH (mm²), geometric mean (C.I.)				p-value
A/H1N1/California	18.3 (14.2–23.7)	19.6 (17.5–22.0)	19.1 (15.5–23.6)	21.2 (19.2–23.4)	0.5	0.5
	IFN-γ (pg/mL), mean
A/H1N1/Brisbane	99	144	168	172	*0.04*	0.6
A/H1N1/Solomon	85	122	152	153	*0.03*	0.3
A/H3N2/Uruguay	137	190	221	245	0.12	0.3
A/H3N2/Wisconsin	162	206	226	261	0.3	0.2
A/H5N1/Vietnam	325	361	377	373	0.4	0.9
B/Florida	204	265	260	289	*0.04*	0.4
B/Malaysia	154	173	164	212	0.14	0.2
M1	24	37	35	33	0.14	0.14
M2	18	18	19	21	0.7	0.7
CFP-10	20	22	18	23	0.4	0.3
PHA	518	512	545	544	0.6	0.5
N	57	175	57	175
Mean age, years	50	38	50	38	<0.001	<0.001

The Wilcoxon-Mann–Whitney rank-sum test was used to calculate p-values. ¹V/NV: vaccinated vs. unvaccinated. Listed are Ab responses (top panel, directed against A/H1N1 California, mean and confidence interval) and IFN-γ responses directed against a broad panel of flu targets (designated the flu A or flu B strains), and against matrix proteins M1 and M2. CFP10 served as a control. PHA was the positive control stimulus. P values below 0.05 are indicated in bold.

ISSN: 1471-2334