Field seasonal influenza vaccine effectiveness

Figures & data

Table 1. Description of laboratory-confirmed influenza and ILI cases included in the study

Groups, age (years)	Total described No.	Total vaccinated No. (%)
ILI patients
6m-64 y.o. with chronic illness	211	24 (11)
≥ 65 y.o.	214	78 (36)
All target groups	425	102 (24)
Laboratory-confirmed influenza patients
All influenza viruses
6m-64 y.o. with chronic illness	10	0 (0)
≥ 65 y.o.	27	10 (37)
All target groups	37	10 (27)
A(H1N1)pdm09
6m-64 y.o. with chronic illness	5	0 (0)
≥ 65 y.o.	5	1 (20)
All target groups	10	1 (10)
A(H3N2)
6m-64 y.o. with chronic illness	1	0 (0)
≥ 65 y.o.	2	1 (50)
All target groups	3	1 (33)
B
6m-64 y.o. with chronic illness	4	0 (0)
≥ 65 y.o.	20	8 (40)
All target groups	24	8 (33)

Table 2. Estimates of field vaccine effectiveness (FVE) of trivalent influenza vaccine against laboratory confirmed influenza and ILI infections during periods of influenza circulation in France, 2010/2011 using administrative data of CNAMTS

Groups, age (years)	VE (%)	95% IC
ILI patients
6m-64 y.o. with chronic illness	65	48 to 78
≥ 65 y.o.	51	35 to 63
All target groups	56	45 to 65
Laboratory-confirmed influenza patients
All influenza viruses
6m-64 y.o. with chronic illness	100	-
≥ 65 y.o.	49	-9 to 78
All target groups	59	17 to 81
A(H1N1)pdm09
6m-64 y.o. with chronic illness	100	-
≥ 65 y.o.	79	-45 to 99
All target groups	85	17 to 99
B
6m-64 y.o. with chronic illness	100	-
≥ 65 y.o.	43	-38 to 78
All target groups	50	-16 to 80

Table 3. Vaccination coverage available among target groups in France, 2010/2011, according three sources of data

Methodology	Origin of data	VC by age groups (95% IC)
		6 m-64 y.o. with chronic illness	≥ 65 y.o.
Administrative data	CNAMTS administrative data (general population)	26.8%	53.8%
Cross-sectional national telephone survey	French Institute for public health surveillance's survey (general population)	46.6% (39.7–53.6)	61.0% (56.7–65.0)
Standardized survey on a randomly assigned single day in general practice	GPs patients of the French Sentinelles Network (GPs’ patients population)	46.0% (40.0–51.0)	72.0% (70.0–75.0)

Table 4. Estimates of field vaccine effectiveness (FVE) of trivalent influenza vaccine against laboratory confirmed influenza during periods of circulation in France by using three sources of vaccination coverages, 2010/2011

Origin of data	FVE(95% CI)
	6 m-64 y.o. with chronic illness	≥ 65 y.o.	All target groups
CNAMTS administrative data (general population)	100	49 (-9 to 78)	59 (17 to 81)
Cross-sectional national telephone survey (general population)	100	62 (19 to 83)	73 (45 to 87)
Standardized survey on a randomly assigned single day in general practice (GPs’ patients population)	100	77 (51 to 90)	82 (63 to 92)