. 2020 Mar 12;25(10):2000153. doi: 10.2807/1560-7917.ES.2020.25.10.2000153

Table 2. Interim vaccine effectiveness (VE) against all laboratory-confirmed influenza, influenza A, A(H1N1)pdm09, A(H3N2) and B, by age group, target group for vaccination and by study, six European studies, influenza season 2019/20.

Influenza (sub)type and study	Setting	Study population^a	Cases			Controls			VE^b	95% CI
Influenza (sub)type and study	Setting	Study population^a	All	Vacc	%	All	Vacc	%	VE^b	95% CI
All influenza (A and B)
DK-PC^c	PC	All ages	1,715	119	7	11,127	1,349	12	56	46 to 65
		0–17 years	669	1	< 1	3,793	669	18	95	67 to 99
		18–64 years	862	48	6	5,436	480	9	58	43 to 69
		≥ 65 years	184	70	38	1,898	808	43	40	18 to 57
ES-PC	PC	All ages	955	46	5	843	79	9	61	37 to 76
		0–14 years	416	14	3	298	15	5	67	18 to 87
		15–64 years	513	19	4	473	27	6	55	10 to 77
		Target group^d	105	27	26	181	57	31	60	22 to 79
EU-PC	PC	All ages	1,052	76	7	1,935	211	11	53	34 to 67
		0–17 years	419	12	3	810	28	4	64	16 to 85
		18–64 years	566	33	6	920	81	9	51	21 to 70
		Target group^d	197	52	26	509	158	31	53	26 to 70
UK-PC	PC	All ages	782	114	15	1,766	308	17	29	4 to 48
		2–17 years	303	24	8	358	28	8	37	−21 to 67
		18–64 years	379	44	12	937	119	13	36	1 to 58
		≥ 65 years	72	46	64	281	161	57	26	−44 to 62
DK-H^c	H	All ages	658	168	26	10,103	2,745	27	40	27 to 51
		18–64 years	237	30	13	3,397	533	16	48	22 to 65
		≥ 65 years	315	134	43	5,008	2,166	43	35	17 to 49
EU-H^c	H	≥ 65 years	128	54	42	473	312	66	60	39 to 74
Influenza A
DK-PC	PC	All ages	1,540	115	8	11,127	1,349	12	54	43 to 63
		0–17 years	579	1	< 1	3,793	61	2	95	63 to 99
		18–64 years	786	47	6	5,436	480	9	54	38 to 67
		≥ 65 years	175	67	38	1,898	808	43	41	18 to 57
ES-PC	PC	All ages	670	40	6	843	79	9	60	34 to 76
		0–14 years	244	12	5	298	15	5	48	−39 to 81
		15–64 years	400	15	4	473	27	6	62	20 to 82
		Target group^d	90	23	26	181	57	31	62	24 to 82
EU-PC	PC	All ages	746	67	9	1,906	210	11	53	32 to 67
		0–17 years	261	10	4	800	28	4	53	−19 to 81
		18–64 years	426	27	6	903	81	9	60	32 to 76
		Target group^d	161	46	29	503	157	31	49	16 to 69
UK-PC	PC	All ages	756	110	15	1,766	308	17	30	4 to 49
		2–17 years	294	23	8	358	28	8	39	−19 to 69
		18–64 years	364	42	12	937	119	13	38	3 to 60
		≥ 65 years	70	45	64	281	161	57	24	−49 to 61
DK-H	Hospital	All ages	629	162	26	10,103	2,745	27	41	27 to 52
		18–64 years	226	29	13	3,397	533	16	47	21 to 65
		≥ 65 years	306	129	42	5,008	2,166	43	37	19 to 50
EU-H^c	Hospital	≥ 65 years	122	50	41	473	312	66	62	41 to 76
Influenza A(H1N1)pdm09
DK-PC	PC	All ages	373	14	4	11,127	1,349	12	75	57 to 86
		18–64 years	229	10	4	5,436	480	9	67	38 to 83
		≥ 65 years	28	4	NC	1,898	808	43	79	37 to 93
ES-PC	PC	All ages	566	30	5	843	79	9	69	46 to 82
		0–14 years	198	10	5	298	15	5	51	−45 to 83
		15–64 years	349	12	3	473	27	6	68	28 to 86
		Target group^d	76	17	22	181	57	31	73	40 to 88
EU-PC	PC	All ages	487	33	7	1,906	210	11	48	18 to 68
		0–17 years	172	9	5	786	27	3	46	−51 to 80
		18–64 years	292	14	5	903	81	9	49	1 to 74
DK-H	Hospital	All ages	132	22	17	10,103	2,745	27	54	24 to 72
		18–64 years	68	8	12	3,397	533	16	55	3 to 79
		≥ 65 years	44	12	NC	5,008	2,166	43	51	4 to 75
EU-H^c	Hospital	≥ 65 years	98	42	43	445	303	68	63	40 to 77
Influenza A(H3N2)
DK-PC	PC	All ages	418	45	11	11,127	1,349	12	27	−4 to 49
		18–64 years	190	17	9	5,436	480	9	29	−19 to 57
		≥ 65 years	55	27	NC	1,898	808	43	12	−53 to 49
ES-PC	PC	All ages	75	10	13	799	79	10	−58	−338 to 43
EU-PC	PC	All ages	244	33	14	1,772	180	10	57	27 to 75
		18–64 years	125	12	10	834	75	9	71	37 to 87
		Target group^d	70	28	40	431	126	29	38	−21 to 69
UK-PC	PC	All ages	675	103	15	1,766	308	17	25	−3 to 46
		2–17 years	273	22	8	358	28	8	39	−21 to 69
		18–64 years	308	38	12	937	119	13	31	−8 to 56
		≥ 65 years	66	43	65	281	161	57	21	−56 to 60
DK-H	Hospital	All ages	154	59	38	10,103	2,745	27	−13	−58 to 19
DK-H	Hospital	≥ 65 years	89	53	60	5,008	2,166	43	−16	−80 to 25
EU-H^c	Hospital	≥ 65 years	12	4	NC	313	199	64	60	−69 to 90
Influenza B
DK-PC	PC	All ages	183	4	2	11,127	1,349	12	83	51 to 94
ES-PC	PC	All ages	285	6	2	843	79	9	66	7 to 87
EU-PC	PC	All ages	305	9	3	1,373	169	12	62	17 to 83
EU-PC	PC	18–64 years	138	6	4	658	64	10	12	−135 to 67
Influenza B Victoria
EU-PC^c	PC	All ages	209	5	2	1,190	141	12	60	−12 to 86

CI: confidence interval; DK-PC: Denmark primary care study; DK-H: Denmark hospital study; ES-PC: Spain primary care study; EU-H: European Union hospital multicentre I-MOVE study; EU-PC: European Union primary care multicentre I-MOVE study; I-MOVE: Influenza - Monitoring Vaccine Effectiveness in Europe; LAIV4: quadrivalent live attenuated influenza vaccine; NC: not calculated (percentages not shown where denominators < 60); PC: primary care; UK-PC: United Kingdom primary care study; Vacc: vaccinated; VE: vaccine effectiveness.

Countries included in EU-H analysis for any influenza, influenza A and influenza A(H3N2): Romania and Spain. For analysis against influenza A(H1N1)pdm09: Spain only.

Countries included in EU-PC analysis for all influenza, influenza A and A(H1N1)pdm09: France, Germany, Ireland, the Netherlands, Portugal, Romania, Spain and Sweden. For analysis against influenza A(H3N2): France, Germany, Ireland, the Netherlands, Romania, Spain and Sweden are included. For analysis against influenza B: France, Germany, Ireland, Portugal, Romania, Spain and Sweden. For analysis against influenza B/Victoria: France, Germany, Ireland, Portugal, Romania and Sweden.

^a Age-specific or target group-specific VE was not included for overall or (sub)type-specific VE in some study sites, where sample size did not allow estimation of VE.

^b For details of adjustment variables, see Table 1.

^c Some records with missing values were dropped from this analysis.

^d Groups targeted by seasonal influenza vaccination as defined locally in the studies and study sites.