Immunogenicity, effectiveness and safety of combined hepatitis A and B vaccine: a systematic literature review

Figures & data

Table 1. Three presentations of combined vaccine against hepatitis A and B.

Vaccine	Target population	Formulation	Schedule
Twinrix^TM	Adults	1.0 ml containing 720 EL.U inactivated HAV and 20 µg recombinant HBsAg protein	3 doses
Twinrix Pediatric^TM	Children (1–11 years)	0.5 ml containing 360 EL.U inactivated HAV and 10 µg recombinant HBsAg protein	3 doses
Ambirix^TM	Children and adolescents (1–15 years)	1.0 ml containing 720 EL.U inactivated HAV and 20 µg recombinant HBsAg protein	2 doses

EL.U: Enzyme-linked immunoassay units; HAV: Hepatitis A virus; HBsAg: Hepatitis B surface antigen.

Figure 1. Flow chart of the selection procedure.

Table 2. Immunogenicity of Twinrix^TM in adults.

Author	Immunized subjects	Schedule	Time point, months	Anti-HAV response				Anti-HBs response
	Study population; country; age			Seropositivity		GMC		Seroprotection*				GMC
Ambrosch [18]	Young adults, mostly medical students (N = 54); Austria; NR	3 doses at 0, 1, and 6 months	1	98		–		56				–
			2	100		–		98				–
			6	100		–		100				–
			7	100		–		100				–
Bruguera [19]	Students of medicine or nursery (N = 150); Spain; Mean (range): 20 years (18–31)	3 doses at 0, 1, and 6 months						≥1 mIU/ml		≥10 mIU/ml
			1	98.7		394		79.9		–		16
			2	100.0		1311		98.0		–		104
			6	100.0		557		100.0		–		297
			7	100.0		8895		100.0		99.3		7097
Czeschinski [20]	Job starters (N = 300); Germany; Mean (range): 21.8 years (18–30)	3 doses at 0, 1, and 6 months	7	100		5864		99.5				4889
De Schrijver [21]	Adult workers (N = 179); Belgium; Mean: 41.1 years	3 doses at 0, 1, and 6 months						≥1 mIU/ml		≥10 mIU/ml
			6	–		–		91.6		79.9		41.7
			7	–		–		99.4		97.1		749.0
Höhler [22]	Adult twins (N = 98); Germany; Mean: 54 years	3 doses at 0, 1, and 6 months and booster at 33 months	7	100		3019.0		100				1459.1
			Y2.5	100		475.0		70.7				128.6
Joines [23]	Adults (N = 829); US; Mean (range): 39.9 years (19–70)	3 doses at 0, 1, and 6 months	1	91.6		335		17.9				8
			2	97.7		636		61.2				23
			6	98.1		367		86.3				118
			7	99.6		4756		95.1				2099
Kallinowski [12]	Adults (N = 49); Germany; 18–50 years	3 doses at 0, 1, and 6 months	2	100		928		80				30
			6	100		487		88				157
			7	100		6125		100				3709
	HCV-positive adults (N = 34); Germany; 18–58 years	3 doses at 0, 1, 6, months	2	29		17		12				49
			6	71		173		65				72
			7	88		2455		82				1472
Kallinowski [24]	Anti-HAV and anti-HBs negative adults (N = 50); Germany; Mean (range): 30.5 years (18–49)	3 doses at 0, 1, and 6 months	1	90		471		28				58
			2	98		–		50				–
			7	100		5123		94				7314
Knoll [25]	Young medical students and staff members (N = 282); Germany; 17–39 years	3 doses at 0, 1, and 6 months	Anti-HAV status pre-immunization			Negative	Positive	≥1 mIU/ml		≥10 mIU/ml		Negative	Positive
								Negative	Positive	Negative	Positive
			7	100		6238	35481	100	100	100	100	9454	18288
Rendi-Wagner [26]	Adolescents and adults seeking pre-travel immunization advice (N = 990); Austria; Mean (range): 43.4 years (6–80)	3 doses at 0, 1, and 6–12 months	NR (GMC <6 months after 3rd dose)	–		–		92.3				1008
Rieger [27]	Adults (N = 304); Germany; Mean (range): 28.5 years (18–45)	3 doses at 0, 1, and 6 months		<40 years	≥40	<40 years	≥40	≥1 IU/l		≥10 IU/l
			1	91.2	82.4	91.3	68.8	34.6		23.8		1.72
			2	98.2	100.0	281.6	209.1	85.2		61.2		14.2
			6	99.1	100.0	184.0	151.4	96.9		94.7		106.8
			7	100.0	100.0	2940.5	1617.1	98.4		97.6		1684.0
Thoelen [11]	Adults (N = 843); Belgium, Lithuania, the Netherlands, Spain, Switzerland; Mean (range): 20.8 years (17–60)	3 doses at 0, 1, and 6 months						≥1 mIU/ml		≥10 mIU/ml
			1	94.3		306		70.6		33.7		10
			2	99.5		748		97.4		83.9		62
			6	99.3		434		99.2		96.7		236
			7	100.0		5404		99.7		99.3		4814
			24	100.0		1044		–		97.7		328
			36	100.0		948		–		97.9		240
			48	100.0		752		–		95.3		211
Van der Wielen [28]/Chilbek [29]	Seronegative adults (N = 596); Belgium, Czech Republic, Germany; Mean (range): 55.2 years (41–81)	3 doses at 0, 1, and 6 months						≥3.3 mIU/ml		≥10 mIU/ml
			7	97.2		2747		92.8		91.7		1154
			Y4	97.3		212.9		76.9		57.1		42.3
Van Herck [30]/Van Damme, 2012 [14]	Adults (N = 223); Belgium; 17–43 years	3 doses at 0, 1, and 6 months	Center	1	2	1	2	1		2		1	2
			7	100.0	100.0	4610.0	6591	100.0		100.0		2637.3	6601
			Y1.5	100.0	100.0	1071.2	1824	95.7		98.8		288.4	710
			Y2	100.0	100.0	854.3	1330	97.7		97.3		236.8	476
			Y3	100.0	100.0	733.7	1383	98.8		96.3		173.6	383
			Y4	100.0	100.0	571.7	1164	95.8		93.9		138.6	410
			Y5	100.0	100.0	580.5	905	96.9		93.0		115.8	330
			Y6	100.0	100.0	541.7	977	89.4		95.0		89.9	322
			Y6*	100.0	100.0	457.0	769.7	96.1		95.0		143.3	416.7
			Y7	100.0	100.0	400.5	833.0	97.8		91.4		140.9	391.2
			Y8	100.0	100.0	343.7	597.5	100.0		91.4		138.3	362.8
			Y9	100.0	100.0	343.6	573.0	97.5		89.3		125.6	451.5
			Y10	100.0	100.0	373.9	674.6	94.1		86.2		103.8	320.4
			Y11	100.0	100.0	–	–	100.0		92.0		–	–
			Y12	100.0	100.0	–	–	97.0		89.3		–	–
			Y13	100.0	100.0	–	–	100.0		87.0		–	–
			Y14	100.0	100.0	–	–	96.7		87.5		–	–
			Y15	100.0	100.0	–	–	92.9		89.3		–	–
Williams [31]	Residents of two nursing facilities (N = 225); US; 45–101 years	3 doses at 0, 1, and 6 months	30–60 days after complete vaccination	–		–		34				5.79
Wolters [32]	Adults (N = 248); Germany; Mean (range): 39.9 years (16–75)	3 doses at 0, 1, and 6 months	Following vaccination	96.2		–		88.7**				–
Wolters [33]	Adults (N = 104); Germany; Mean (range): 54 years (17–84)	3 doses at 0, 1, and 6 months	Following vaccination	71.2		–		37.5				–

GMC: Geometric mean concentration; HAV: Hepatitis A virus; HBs: Hepatitis B surface protein; HCV: Hepatitis C virus; NR: Not reported; Y: Years; -: Not reported.

Data from multiple articles regarding the same study were combined in the table. All relevant references are stated under ‘Author’.

*All rates are seroprotection, unless clearly stated as seropositivity (i.e. ≥1 mIU/ml).

**Seroprotection was defined as at least 100 IU/l anti-HBs detected [32].

Table 3. Immunogenicity of Twinrix^TM in children.

Author	Immunized subjects	Schedule	Time point, months	Anti-HAV response				Anti-HBs response
	Study population; country; age			Seropositivity		GMC		Seropositivity/protection		GMC
Flynn [16]	HIV-infected youth (N = 118); Bahamas, Brazil, South Africa, US; Mean (range): 20.4 years (12–25)	3 doses at 0, 1, and 6 months	7	–		–		75.4*		97.7
Thompson [34]	Adolescents (N = 160); Australia; Mean: 16.4 years	3 doses at 0, 1, and 6 months (2 lots)		Lot 1	Lot 2	Lot 1	Lot 2	Lot 1	Lot 2	Lot 1	Lot 2
			1	92.3	89.5	254	221	55.1	55.3	13	11
			2	100.0	98.7	574	665	89.7	97.3	29	25
			6	100.0	97.4	307	377	97.4	100.0	238	214
			7	100.0	100.0	5694	6260	98.7	100.0	4316	4436

GMC: Geometric mean concentration; HAV: Hepatitis A virus; HBs: Hepatitis B surface protein; HIV: Human immunodeficiency virus; -: Not reported.

*Outcomes and vaccine response were reported as IU/ml. However, we assume that the outcome measure should be mIU/ml. For the purpose of this review, data are handled as mIU/ml.

Table 4. Immunogenicity of Twinrix^TM following an alternative schedule.

Author	Immunized subjects	Schedule	Time point, months	Anti-HAV response				Anti-HBs response
	Study population; country; age			Seropositivity		GMC		Seroprotection*		GMC
Connor [35]	Adults (N = 250); US, Norway, Belgium, Czech Republic; ≥18 years	4 doses at 0, 7, 21–30, and 12 months	Day 37	98.5		454.6		63.2		15.7
			3	100.0		480.6		83.2		53.4
			12	96.9		–		82.1		–
			13	100.0		7110.5		96.4		7648.1
De Schrijver [21]	Adult workers (N = 194); Belgium; Mean: 42.5 years	3 doses at 0, 1, and 12 months						≥1 mIU/ml	≥10 mIU/ml
			6	–		–		89.2	70.6	43.7
			12	–		–		81.2	55.9	30.2
			13	–		–		98.9	95.6	1900.6
Frey [36]	Individuals (N = 1251); NR; Median (range): 23 years (10–80)	2 doses at 0 and 6 months	1	93.0		36		5.4		0.5
			7	100		5104		84.2		169
			12	99.7		1637		75.9		33
Kallinowski [12]	HCV-positive adults and healthy volunteers (N = 95); Germany; 18–58 years	3 doses at 0, 7, and 21 days		Healthy	HCV	Healthy	HCV	Healthy	HCV	Healthy	HCV
			Day 21	87	39	58	47	39	10	46	53
			2	100	89	424	158	98	77	835	302
			6	100	90	1416	561	98	73	808	297
Nothdurft [37]	Seronegative adults (N = 211); Germany; 18–45 years	4 doses at 0, 7, and 21 days and 12 months	1	100		845		82.0		65
			2	99.5		780		85.0		53
			3	100		628		95.2		183
			12	96.2		374		94.0		209
			13	100		9571		100		26002

GMC: Geometric mean concentration; HAV: Hepatitis A virus; HBs: Hepatitis B surface protein; HCV: Hepatitis C virus; -: Not reported.

*All rates are seroprotection, unless clearly stated as seroconversion (i.e. ≥1 mIU/ml).

Table 5. Immunogenicity of Twinrix Pediatric^TM in children and adolescents.

Author	Immunized subjects	Schedule	Time point/age cohort	Anti-HAV response				Anti-HBs response
	Study population; country; age			Seropositivity		GMC		Seroprotection*		GMC
Levie [38]/Beran [15]	Adolescents (N = 148); Belgium, Czech Republic; Mean (range): 13.4 years (12–15)	3 doses at 0, 1, and 6 months	1	93.2		227		29.1		10
			2	99.3		549		85.6		42
			6	99.3		299		98.0		305
			7	100		4174		100		5054
			7**	100		4516		100		4865
			24**	100		725		96.2		337
			120**	100		335.5		85.1		60.1
Ostergaard [39]	Adolescents (N = 122); Denmark, Sweden; Mean (range): 14.3 years (11–17)	3 doses at 0, 1, and 6 months		HAB	MTT + HAB	HAB	MTT + HAB	HAB	MTT + HAB	HAB	MTT + HAB
			0	2.0	3.0	7.6	7.9	0.0	0.3	1.7	1.7
			7	100	100	6739.0	5876.7	100	99.1	7654.7	6088.2
Pedersen [40]	Girls (N = 520); Canada, Denmark, Hungary, Sweden; 11.2 years	3 doses at 0, 1, and 6 months		HAB	HPV + HAB	HAB	HPV + HAB	HAB	HPV + HAB	HAB	HPV + HAB
			7	100	100	5288.4	4504.2	100	98.3	5646.5	3136.5
Roberton [41] /Marshall [10]	Children (N = 191); Australia, Belgium, Spain, Sweden; 1–11 years	3 doses at 0, 1, and 6 months	7	100		9257		100		13,683
			60	100		698.4		97.0		283.7
Van Damme [42]/Diaz Mitoma [43]	Children (N = 166); Canada; 1–15 years	3 doses at 0, 1, and 6 months		1–6 years	6–15 years	1–6 years	6–15 years	1–6 years	6–15 years	1–6 years	6–15 years
			7	100	100	6518	8499	100	100	7255	10513
			36	100	100	761	1250	97.5	98.9	339	518
			48	100	100	653	937	97.5	98.5	297	421
			60	100	100	479	881	97.4	95.2	195	263
			90	100	100	233	702	86.5	92.9	147	297
			120	–	100	–	680	–	95.5	–	162

GMC: Geometric mean concentration; HAV: Hepatitis A virus; HAB: Hepatitis A and B vaccine; HBs: Hepatitis B surface protein; HPV: Human papillomavirus; MTT: Tetravalent meningococcal conjugate vaccine having each of the polysaccharide coupled to tetanus toxoid; -: Not reported.

*All rates are seroprotection, unless clearly stated as seroconversion (i.e. ≥1 mIU/ml).

**Tests performed with new kits or equivalent validated in-house enzyme-linked immunosorbent assay (ELISA).

Data from multiple articles regarding the same study were combined in the table. All relevant references are stated under ‘Author’.

Table 6. Immunogenicity of Twinrix Pediatric^TM in children following an alternative schedule.

Author	Immunized subjects	Schedule	Time point/age cohort	Anti-HAV response		Anti-HBs response
	Study population; country; age			Seropositivity	GMC	Seropositivity/protection		GMC
Duval [44]/Gilca [45]	Children (N = 347); Canada; 8–10 years	2 doses at 0 and 6 months and challenge dose at Y7				≥1 mIU/ml	≥10 mIU/ml
			Post-second dose	100	–	97.1	96.5	3248
			Pre-challenge dose	97.8	275	92	75.1	60
			Post-challenge dose	100	8203	–	100	39573

GMC: Geometric mean concentration; HAV: Hepatitis A virus; HBs: Hepatitis B surface protein; -: Not reported.

Data from multiple articles regarding the same study were combined in the table. All relevant references are stated under ‘Author’.

Table 7. Immunogenicity of Ambirix^TM in children and adolescents.

Author	Immunized subjects	Schedule	Time point, months	Anti-HAV response				Anti-HBs response
	Study population; country; age			Seropositivity		GMC		Seroprotection*		GMC
Belderok [46]	Children with HIV and children receiving IM for rheumatic diseases (N = 160); the Netherlands; 1–16 years	2 doses at 0 and 26-30 weeks		HIV	IM	HIV	IM	HIV	IM	HIV	IM
			Dose 1	71	55	40	31	27	17	5	3
			Dose 2	99	100	327	288	97	93	483	321
Burgess [47]/Burgess [48]	Adolescents (N = 106); Australia; 12–15 years	2 doses at 0 and 6 months	1	98.1		365		43.4		17
			6	95.2		140		59.0		17.3
			7	100.0		5991.7		98.1		2791.4
			24	100.0		743.5		91.0		248.2
			36	98.8		620.3		81.9		149.3
			60	98.1		536.3		81.5		81.5
			72	100.0		529.0		84.8		108.7
Cunningham [49]	HIV-negative urban youth (N = 63); US; 15.2 years	2 doses at 0 and 6 months	7	–		–		94.6		–
Lee [50]	Youngsters (N = 51); China; 10–19 years	2 doses at 0,6 months						≥1 mIU/ml	≥10 mIU/ml
			1	98.0		379		61.2	51.0	55
			2	95.9		210		73.5	40.8	19
			6	85.7		122		79.6	51.0	17
			7	100		3701		93.9	91.8	1524
Levie [38]/Beran [15]	Adolescents (N = 142); Belgium, Czech Republic; Mean (range): 13.4 years (12–15)	2 doses at 0 and 6 months	1	99.3		349		43.0		14
			2	100		245		38.0		10
			6	100		178		68.3		20
			7	100		5487		97.9		4949
			7*	100		5242		99.3		4922
			24*	100		943		93.3		359
			120*	100		429.3		85.9		50.6
Ramonet [51]	Children and adolescents (N = 168); Argentina, Brazil, Mexico; 4–20 years	2 doses at 0 and 6 months	1	96.9		502		43.7		16
			2	98.1		284		55.6		18
			6	93.0		185		67.5		32
			7	100		6635		98.7		3362
Roberton [41] /Marshall [10]	Children (N = 204); Australia, Belgium, Spain, Sweden; 1–11 years	2 doses at 0 and 6 months	7	100		8412		98.5		7894
			60	100		576.8		94.1		150.2
Usonis [52]**	Infants (N = 90); Estonia, Lithuania; 11–18 months	2 doses at 0 and 6 months		Group 1	Group 2	Group 1	Group 2	Group 1	Group 2	Group 1	Group 2
			0	0.0	2.7	17	17	0.0	0.0	0.5	0.5
			7	100.0	100.0	8736	11016	100.0	100.0	23092	32540
Van Damme 2011 [53]	Children (N = 232); Belgium; 1–11 years	2 doses at 0 and 6 months	7	100		14790.1		98.5		9389.1
			36	100		1281.6		95.0		338.8
			48	100		874.1		89.9		264.5
			60	100		721.1		85.8		187.0
			72	100		692.3		81.7		206.2
			84	100		753.6		84.6		157.5
			96	100		544.4		81.1		102.7
			108	100		479.5		87.6		89.1
			120	100		601.6		81.7		80.7
Van der Wielen [54]	Children (N = 236); Belgium; 1–11 years	2 doses at 0 and 6 months		<6 y	≥6 y	<6 y	≥6 y	<6 y	≥6 y	<6 y	≥6 y
			1	100	99.2	339	493	22.1	34.6	5	10
			2	95.7	100	264	308	59.9	40.5	14	9.5
			6	100	96.9	202	189	84.8	74.8	48	28
			7	100	100	12050	11293	98.5	98.5	8985	7622

GMC: Geometric mean concentration; HAV: Hepatitis A virus; HBs: Hepatitis B surface protein; HIV: Human immunodeficiency virus; IM: Immunosuppressive medication; -: Not reported.

*All rates are seroprotection, unless clearly stated as seroconversion (i.e. ≥1 mIU/ml).

**In group 1, Ambirix^TM was administered concomitantly with DTPa-IPV/Hib vaccine. In group 2, Ambirix^TM was administered concomitantly with MMR vaccine.

Data from multiple articles regarding the same study were combined in the table. All relevant references are stated under ‘Author’.

Table 8. Immunogenicity of Ambirix^TM in adolescents following an alternative schedule.

Author	Immunized subjects	Schedule	Time point, months	Anti-HAV response		Anti-HBs response
	Study population; country;aAge			Seropositivity	GMC	Seroprotection*	GMC
Burgess [47] /Burgess [48]	Adolescents (N = 102); Australia; 12–15 years	2 doses at 0 and 12 months	1	99.0	293.9	34.3	15.0
			12	84.2	146.5	50.5	16.1
			13	99.0	8471.8	97.0	4339.5
			24	98.8	1704.7	93.8	569.6
			36	98.8	1273.6	87.2	400.5
			60	100.0	880.6	93.0	213.5
			72	100.0	932.6	92.9	231.9

GMC: Geometric mean concentration; HAV: Hepatitis A virus; HBs: Hepatitis B surface protein.

*All rates are seroprotection, unless clearly stated as seroconversion (i.e. ≥1 mIU/ml).

Data from multiple articles regarding the same study were combined in the table. All relevant references are stated under ‘Author’.

Table 9. Comparison between Twinrix^TM and concomitant administration of monovalent hepatitis A and B vaccines.

Author	Population	Vaccine and schedule		Time point	Anti-HAV response							Anti-HBs response
					Seropositivity			GMC				Seroprotection*							GMC
Ambrosch [18]	Young adults, mostly medical students; N = 162 (3 x 54); Age: NR	[1] Twinrix^TM: 3 doses at 0, 1, and 6 months [2] Havrix^TM + Engerix-B^TM (Simultaneous): 3 doses at 0, 1, and 6 months [3] Havrix^TM + Engerix-B^TM (Mixed): 3 doses at 0, 1, and 6 months		Vaccine	[1]	[2]	[3]					[1]		[2]			[3]
				1	98	98	100	–				56		78			65		–
				2	100	100	100	–				98		96			98		–
				6	100	98	100	–				100		100			98		–
				7	100	100	100	–				100		100			100		–
Connor [35]	Adults; N = 496; Age ≥18 years	[1] Twinrix^TM: 4 doses at 0, 7, and 21–30 days and 12 months [2] Havrix^TM + Engerix-B^TM: 2 and 4 doses at 0 (1, 2), and 12 months		Vaccine	[1]	[2]		[1]	[2]			[1]		[2]					[1]		[2]
				Day 37	98.5	98.6		454.6	241.7			63.2		43.5					15.7		7.5
				3	100.0	95.6		480.6	120.7			83.2		76.7					53.4		52.2
				12	96.9	86.9		–	–			82.1		77.8					–		–
				13	100.0	100.0		7110.5	3235.7			96.4		93.4					7648.1		4380.9
Czeschinski [20]	Job starters; N = 300; Mean age (range): 21.8 years (18–30)	[1] Twinrix^TM: 3 doses at 0, 1, and 6 months [2] Havrix^TM + Engerix-B^TM: 3 doses at 0, 1, and 6 months [3] Havrix^TM or Engerix-B^TM: 3 doses at 0, 1, and 6 months		Vaccine				[1]	[2]		[3]								[1]		[2]	[3]
				7	–			5997	5864		2707	–							4889		8212	4931
Flynn [16]	HIV-infected youth; N = 336; Mean age (range): 20.4 years (12–25)	[1] Twinrix^TM: 3 doses at 0, 1, and 6 months [2] Engerix-B^TM 20 mcg: 3 doses at 0, 1, and 6 months [3] Engerix-B^TM 40 mcg: 3 doses at 0, 1,and 6 months		Vaccine								[1]		[2]			[3]		[1]		[2]	[3]
				7	–			–				75.4		60			73.2		97700		52500	77600
Frey [36]	Individuals; N = 1385; Median age (range): 23 years (10–80)	[1] Twinrix^TM: 2 doses at 0,6 months [2] Vaqta + Recombivax-HB: 2 doses at 0 and 6 months		Vaccine	[1]	[2]		[1]		[2]		[1]		[2]					[1]		[2]
				1	93.0	89.1		36		31		5.4		7.9					0.5		0.7
				7	100	99.2		5104		3555		84.2		91.8					169		588
				12	99.7	99.2		1637		1263		75.9		83.6					33		110
Joines [23]	Adults; N = 829; Mean age (range): Twinrix^TM: 39.9 years (19–70)/Havrix^TM + Engerix-B^TM: 40.4 years (19–83)	[1] Twinrix^TM: 3 doses at 0, 1, and 6 months [2] Havrix^TM + Engerix-B^TM: 3 doses at 0, 1, and 6 months**		Vaccine	[1]	[2]		[1]		[2]		[1]		[2]					[1]		[2]
				1	91.6	98.1		335		444		17.9		7.5					8		6
				2	97.7	98.9		636		257		61.2		50.4					23		18
				6	98.1	98.9		367		196		86.3		75.7					118		45
				7	99.6	99.3		4756		2948		95.1		92.2					2099		1871
Knöll [25]	Young medical students and staff members; N = 282; Age range: 17–39 years	[1] Twinrix^TM: 3 doses at 0, 1, and 6 months [2] Engerix-B^TM: 3 doses at 0, 1, and 6 months	Pre-immunization anti-HAV status	Vaccine	[1]	[2]		[1]		[2]		≥1 mIU/ml		≥10 mIU/ml					[1]		[2]
												[1]	[2]	[1]			[2]
			Negative	7	100	–		6238		–		100	100	100			99		9454		7826
			Positive	7				35481				100	100	100			100		18288		8813
Nothdurft [37]	Seronegative adults; N = 479; Age range: 18–45 years	[1] Twinrix^TM: 4 doses at 0, 7, and 21 days and 12 months [2] Havrix^TM: 2 doses at 0 and 6 months Engerix-B^TM: 4 doses at 0, 7, and 21 days and 12 months		Vaccine	[1]	[2]		[1]		[2]		[1]		[2]					[1]		[2]
				1	100	99.0		845		512		82.0		83.9					65		98
				2	99.5	98.9		780		286		85.0		84.9					53		58
				3	100	97.8		628		219		95.2		90.8					183		131
				12	96.2	95.0		374		170		94.0		91.6					209		106
				13	100	100		9571		5205		100		100					26002		29196
Rendi-Wagner [26]	Adolescents and adults seeking pre-travel immunization advice; N = 1874; Mean age (range): 43.4 years (6–80)	[1] Twinrix^TM: 3 doses at 0, 1, and 6-12 months [2] Engerix-B^TM: 3 doses at 0, 1, and 6–12 months [3] GEN H-B-VAX: 3 doses at 0, 1, and 6–12 months		Vaccine								[1]	[2]			[3]			[1]	[2]	[3]
				<6 months after 3^rd dose**	–			–				92.3	87.7			79.3			1008	523	142
Rieger [27]	Adults; N = 304; Mean age (range): 28.5 years (18–45)	[1] Twinrix^TM: 3 doses at 0, 1, and 6 months [2] Vaqta + GEN H-B-VAX: 3 doses at 0, 1, and 6 months***		Vaccine	[1]	[2]		[1]		[2]			≥1 IU/l			≥10 IU/l			[1]		[2]
													[1]		[2]	[1]		[2]
			<40y	1	91.2	98.1		91.3		173.9		1	34.6		20.0	23.8		8.0	1.72		0.8
				2	98.2	99.0		281.6		157.4
				6	99.1	97.1		184.0		152.3		2	85.2		70.1	61.2		53.2	14.2		6.6
				7	100.0	100.0		2940.5		2500.3
			≥40y	1	82.4	94.7		68.8		108.2		6	96.9		90.3	94.7		79.0	106.8		27.2
				2	100.0	89.5		209.1		83.2
				6	100.0	89.5		151.4		74.5		7	98.4		99.1	97.6		98.4	1684.0		528.2
				7	100.0	100.0		1617.1		1275.6
Van der Wielen [28]/ Chlibek [29]	Seronegative adults; N = 596; Mean age (range): 55.2 years (41–81)	[1] Twinrix^TM: 3 doses at 0, 1, and 6 months [2] Havrix^TM + Engerix-B^TM: 3 doses at 0,1, and 6 months*** [3] Vaqta + HB VAX PRO: 3 doses at 0, 1, and 6 months***		Vaccine	[1]	[2]	[3]	[1]		[2]	[3]	≥3.3 mIU/ml			≥10 mIU/ml				[1]	[2]	[3]
												[1]	[2]	[3]	[1]	[2]		[3]
				7	97.2	98.9	98.9	2747		1394	3707	92.8	83.5	77.8	91.7	79.7		71.0	1154	491	179
				48	97.3	93.9	96.0	212.9		165.7	277.4	76.9	61.9	51.6	57.1	40.1		26.6	42.3	23.6	13.7

GMC: Geometric mean concentration; HAV: Hepatitis A virus; HBs: Hepatitis B surface protein; HIV: Human immunodeficiency virus; NR: Not reported

*All rates are seroprotection, unless clearly stated as seroconversion (i.e. ≥1 mIU/ml).

**Time point meting seroconversion: NR.

***Only two doses of Havrix^TM and/or Vaqta were administered at months 0 and 6.

Data from multiple articles regarding the same study were combined in the table. All relevant references are stated under ‘Author’.

Table 10. Comparison between Twinrix pediatric^TM and concomitant administration of monovalent hepatitis A and B vaccines.

Author	Population	Vaccine and schedule	Time point	Anti-HAV response				Anti-HBs response
				Seropositivity		GMC		Seroprotection		GMC
Duval [44] /Gilca [45]	Children; N = 704; Age 8–10 years	Twinrix pediatric^TM [TX]: 2 doses at 0 and 6 months and challenge dose at Y7 [2] Recombivax-HB [RB]: 2 doses at 0 and 6 months and challenge dose at Y7	Vaccine	[TX]	[RB]	[TX]	[RB]	[TX]	[RB]	[TX]	[RB]
			Post-second dose	100	–	–	–	–	–	3248	742
			Pre-challenge dose	–	–	275	–	75	55	60	12
			Post-challenge dose	–	–	8203	–	100	98	39573	5114

GMC: Geometric mean concentration; HAV: Hepatitis A virus; HBs: Hepatitis B surface protein; RB: Recombivax-HB; TX: Twinrix pediatric^TM; -: Not reported.

Data from multiple articles regarding the same study were combined in the table. All relevant references are stated under ‘Author’.

Table 11. Comparison between Ambirix^TM and concomitant administration of monovalent hepatitis A and B vaccines.

Author	Population	Vaccine and schedule	Time point	Anti-HAV response				Anti-HBs response
				Seropositivity		GMC		Seroprotection*				GMC
Cunningham [49]	HIV-negative urban youth; N = 123; Mean age: 15.2 years	[1] Ambirix^TM: 2 doses at 0 and 6 months	Vaccine					[1]		[2]
		[2] Recombivax-HB: 2 doses at 0and 6 months	1	–		–		94.6		87.2		–
			Week 76	–		–		88.0		81.1		–
Lee [50]	Chinese youngsters; N = 103; Mean age (range): Ambirix^TM: 14.1 y (10-19)/Simultaneous: 12.4 years (10–19)	[1] Ambirix^TM 2 doses at 0 and 6 months	Vaccine	[1]	[2]	[1]	[2]	≥1 mIU/ml		≥10 mIU/ml		[1]	[2]
								[1]	[2]	[1]	[2]
		[2] Unspecified simultaneous hepatitis A and B vaccines: 2 doses at 0 and 6 months	1	98.0	97.9	379	219	61.2	70.2	51.0	48.9	55	36
			2	95.9	91.5	210	136	73.5	70.2	40.8	42.6	19	23
			6	85.7	95.1	122	74	79.6	72.3	51.0	42.6	17	15
			7	100	100	3701	1705	93.9	95.7	91.8	95.7	1524	720
Ramonet [51]	Children and adolescents; N = 248; Age range: 4–20 years	[1] Ambirix^TM: 2 doses at 0 and 6 months [2] Havrix^TM + Engerix-B^TM: 2 doses at 0 and 6 months	Vaccine	[1]	[2]	[1]	[2]	[1]		[2]		[1]	[2]
			1	96.9	97.3	502	342	43.7		28.8		16	13
			2	98.1	94.8	284	188	55.6		48.7		18	22
			6	93.0	91.9	185	134	67.5		68.9		32	26
			7	100	98.6	6635	2728	98.7		95.9		3362	1724

GMC: Geometric mean concentration; HAV: Hepatitis A virus; HBs: Hepatitis B surface protein; HIV: Human immunodeficiency virus; -: Not reported.

*All rates are seroprotection, unless clearly stated as seroconversion (i.e. ≥1 mIU/ml).

Table 12. Solicited and unsolicited adverse events following immunization with Twinrix^TM, Twinrix pediatric^TM, or Ambirix^TM.

Reaction	Twinrix^TM, range	Twinrix pediatric^TM, range	Ambirix^TM, range
Local reactions, %
Any	41.6–65.6 [24,34,35,37]	–	50.4–54.3 [48]
Soreness/pain	10.5–65.6 [12,19–24,27,34,35,37,56]	39.1–52.2 [38–41]	13.8–54.0 [38,41,48,50–52,54]
Redness	0.0–26.0 [12,19–23,27,34,35,37,56]	11.9–30.8 [38,40,41]	1.0–29.4 [38,41,48,50–52,54]
Swelling	0–20.6 [12,19–23,27,34,35,37,56]	4.9–21.1 [38,40,41]	0.8–15.7 [38,41,48,50–52,54]
Systemic reactions, %
Any	2–58.0 [24,34,35,37]	–	40.9 [48]
Fever	0.5–7.8 [12,20,21,23,34,35,37,56]	1.3–15.6 [38,40,41]	1.7–13.3 [38,41,48,50–52,54]
Headache	2.1–38.7 [12,19–23,34,35,37,56]	13.9–42.6 [38,40,41]	7.0–31.5 [38,41,48,50–52,54]
Malaise	0.5–29.0 [12,20,21,34,37,56]	–	7.5 [51]
Fatigue	2.6–42.2 [19,21–23,34,35,37,56]	19.3–32.0 [38,40,41]	5.0–29.2 [38,41,48,50–52,54]
Nausea	1.3–11.9 [12,20,23,24,34,37]	–	4.4 [51]
Vomiting	0–7.0 [12,23,34,37,56]	–	1.2 [51]
Gastrointestinal	1.7–7.5 [21–23,35]	3.4–30.3 [38,40,41]	4.3–22.9 [38,41,48,51,52,54]
SAE, n	0–21 [12,22,23,27,34,35,37]	1–5 [38–41]	0–6 [38,41,48,50–52,54]
Unsolicited events, n	0–109 [19,22,35,37,56]	18–89 [39,41]	0–132 [41,48,50,54]

SAE: Serious adverse event; -: Not reported.

Table A1. Study characteristics.

Reference	Country	Study design	Study population, N, age	Vaccine used	Laboratory test used	Conflict of interest	Main study limitations reported by the authors
Ambrosch J Med Virol 1994 [18]	NR	Comparative study*	Healthy young adults, mostly medical studentsN = 162 (54 subjects received Twinrix^TM)Age: NR	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: Havrix^TM+ Engerix-B^TM3 doses at 0, 1,and 6 months	HAV: HAVAB (Abbott)^a ELISA inhibition assay (SmithKline Beecham Biologicals)^b HBV: AUSAB (Abbott)^c CORAB (Abbott)^a AUSRIA (Abbott)^a	Not reported
Belderok Vaccine 2013 [46]	The Netherlands	Phase IV interventional study	Children known to be infected with HIV and children receiving IM for treatment of rheumatic diseasesN = 160Age range: 1–16 years	Ambirix^TM2 doses at 0, 26–30 weeksComparator: None	HAV: Axsym HAVAB 2.0 (Abbott)^a Anti-HAV Total HAVT (Biomerieux)^a HBV: Axsym CORE (Abbott)^a Axsym AUSAB (Abbott)^a	None	None
Bruguera Vaccine 1996 [19]	Spain	Randomized trial	Healthy young students of medicine or nurseryN = 150Mean age (SD; range): 20 years (1.4; 18–31)	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: None	HAV: ETI-ABHAVK (Sorin Biomédica)^a Enzymum ELISA (Boehringer Mannheim)^d HBV: ETI-AB-COREK (Sorin Biomédica)^a ETI-ABAVK ELISA (Sorin Biomédica)^a ETI-MAK ELISA (Sorin Biomédica)^a AUSAB (Abbott)^c	GSK	None
Burgess Vaccine 2001 [48]Burgess Vaccine 2010 [47]	Australia	Open, randomized study with follow-up	Healthy subjects who had not been previously vaccinated against hepatitis A and BN = 240Age range: 12–15 years	Ambirix^TM2 doses at 0 and 6 months or 0 and 12 monthsComparator: None	HAV: Enzymum ELISA (Boehringer Mannheim)^d Enzygnost (DADE Behring)^e HBV: AUSAB (Abbott)^c,f AUSRIA (Abbott)^a CORAB (Abbott)^a	GSK	Small sample size at 6-year follow-up.
Connor J Travel Med 2007 [35]	Belgium, Czech Republic, Norway, US	Prospective, open-label, randomized, multicenter, comparative study	Healthy adults who were seronegative for anti-HAV, anti-HBs, and anti-HBc antibodies and for HBsAgN = 496 (250 subjects received Twinrix^TM)Age: ≥18 years	Twinrix^TM4 doses at 0, 7, and 21–30 days and 12 monthsComparator: Havrix^TM + Engerix-B^TM2 and 4 doses at 0 (1,2), and 12 months	HAV: Enzyme immunoassay (Behring)^eHBV: AUSAB (Abbott)^f	GSK	None
Cunningham Pediatr Infect Dis J 2010 [49]	US	Phase II, randomized, single-blinded trial	HIV-negative urban youthN = 123 (63 subjects received Twinrix^TM)Mean age (SD): 15.12 years (1.58)	Ambirix^TM2 doses at 0 and 6 monthsComparator: Recombivax HB2 doses at 0 and 6 months	HAV: NAHBV:- EIA (Abbott)^a- ECI (Ortho Vitros)^a	None	Significant loss to follow-up (due to hurricane Katrina).Study was not designed to compare both vaccines.Relatively small sample size
Czeschinski Vaccine 2000 [20]	Germany	Randomized study	Healthy job startersN = 300 (75 subjects received Twinrix^TM)Mean age (range): 21.8 years (18–30)	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: Havrix^TM+ Engerix-B^TM3 doses at 0, 1, and 6 months	HAV: ETI-AB-HAVK-3 (Sorin Biomédica)^bHBV: IMx AUSAB (Abbott)^g	Not reported	Exact antibody titers could be assessed for only 43 of 74 subjects receiving Twinrix
De Schyver J Viral Hepat 2011 [21]	Belgium	Randomized, stratified, controlled study	Healthy adult workers, who are not occupationally exposed to HBVN = 397Mean age: Study group: 42.5 years Reference group: 41.4 years	Twinrix^TM Study group: 3 doses at 0, 1, and 12 months Reference group: 3 doses at 0, 1, and 6 months Comparator: None	HAV: NRHBV:- ETI-AB-AUK-3 (DiaSorin)^c- ETI-AB-CORTEK PLUS (DiaSorin)^c- ETI-MAK-4 (DiaSorin)^c	GSK	None
Dominguez J Viral Hepat 2008 [55]	Spain	Surveillance study	Subjects with viral hepatitisN = 7536All ages	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: None	HAV: NRHBV: NR	None	Possibly underestimation of number of cases, since only reported clinical cases are included in the surveillance system (cases not reported for various reasons and asymptomatic infection will be missed)
Duval Vaccine 2005 [44] GilcaPediatr Infect Dis J2009 [45]	Canada	Open label study	Children eligible to be vaccinated according to the regular immunization program in Quebec cityN = 704 (347 children received Twinrix^TM)Mean age (95% CI): Twinrix^TM: 114 months (108–119) Recombivax-HB: 114 months (109–120)	Twinrix pediatric^TM2 doses + challenge dose at 0 and 6 months + 7 yearsComparator: Recombivax-HB2 doses + challenge dose at 0 and 6 months + 7 years	HAV: HAV Total Assay EIA (Bio-Rad)^dHBV: AUSAB EIA (Abbott)^c ELISA (ORTHO, Raritan)^a EIA 2.0 (Bio-Rad)^a	Not reported	Nonrespondents from the primary study were excluded in the follow up study, which might lead to an overestimation of the response to a challenge dose
Flynn J AIDS 2011 [16]	Bahamas, Brazil, South Africa, US	Randomized trial	HIV-infected youthN = 336 (118 receiving Twinrix^TM)Mean age: 20.44 years	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: Engerix-B^TM20 mcg (recommended) or 40 mcg (increased)3 doses at 0, 1, and 6 months	HAV: NRHBV: Abbott EIA or Ortho Vitros ECI^g	None	None
Frey J Infect Dis 1999 [36]	NR	Open, randomized trial	Healthy individualsN = 1,385 (1252 receiving Twinrix^TM)Median age (range): Twinrix^TM: 23 years (10–80) VAQTA + Recombivax-HB: 22 years (11–59)	Twinrix^TM2 doses at 0 and 24 weeksComparator: VAQTA+ Recombivax-HB2 doses at 0 and 24 weeks	HAV: HAVAB (Abbott)^gHBV: AUSAB RIA (Abbott)^g	Merck and Company Inc.	The wide age range of study participants may have contributed to less-than-optimal response to the combination vaccine
HöhlerVaccine 2007 [22]	NR	Extension of a primary open, prospective, single-site study	Healthy mono- and dizygotic twinsN = 98Mean age (SD): 54 years (7.1)	Twinrix^TM3 doses at 0, 1, and 6 months and booster dose at 33 monthsComparator: None	HAV: Enzygnost (DADE Behring)^eHBV: AUSAB EIA (Abbott)^f	GSK	None
Joines Vaccine 2001 [23]	US	Open-label, randomized, multicenter, controlled clinical trial	Healthy adultsN = 829 (414 subjects received Twinrix^TM)Mean age (range): Twinrix^TM: 39.9 years (19–70) Havrix^TM+ Engerix-B^TM: 40.4 years (19–83)	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: Havrix^TM+ Engerix-B^TM2 and 3 doses at 0 (1), and 6 months	HAV: HABAV (Abbott)^dHBV: AUSAB (Abbott)^c	Not reported	None
Kallinowski Z Gastroenterol 2003 [12]	NR	Open, multicenter study	Caucasian patients with chronic HCV-infection and healthy volunteers (i.e. oversea travelers or healthy hospital staff)N = 178Mean age (SD), years: HCV+/Accelerated: 39 (10) Healthy/Accelerated: 33 (7) HCV+/Standard: 35 (8) Healthy/Standard: 30 (8)	Twinrix^TM Standard: 3 doses at 0, 1, and 6 months Accelerated: 3 doses at 0, 7, and 21 days Comparator: None	HAV: ELISA (Abbott)^dHBV: ELISA (Abbott)^c	None	None
Kallinowski Liver 1996 [24]	Germany	Prospective cohort study*	Anti-HAV and anti-HBs negative volunteersN = 50Mean age (range): 30.5 years (18–49)	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: None	HAV: ELISA (SmithKline Beecham Biologicals)^bHBV: ELISA (SmithKline Beecham Biologicals)^g	Not reported	None
Knöll Vaccine 2000 [25]	Germany	Comparative study*	Healthy young medical students and staff membersN = 282 (134 receiving Twinrix^TM)Age range: 17–39 years	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: Engerix-B^TM3 doses at 0, 1, and 6 months	HAV: AXSYM HAVAB (Abbott)^bHBV:- AXSYM CORE (Abbott)^c- AXSYM AUSAB (Abbott)^c
Lee J Med Virol 1999 [50]	China	Open, randomized study	Healthy Chinese youngstersN = 103 (51 subjects received Twinrix^TM)Mean age (SD; range): Twinrix^TM: 14.1 years (2.68; 10–19) Concomitant: 12.4 years (2.21; 10–19)	Ambirix^TM2 doses at 0 and 6 monthsComparator: Concomitant hepatitis A and B vaccines (not specified)2 doses at 0 and 6 months	HAV: HAVAB (Abbott)^a Enzymun (Boehringer Mannheim)^a HBV: AUSRIA II (Abbott)^a CORAB (Abbott)^a AUSAB (Abbott)^a	GSK	None
Levie Vaccine 2002 [38] Beran Vaccine 2010 [15]	Belgium, Czech republic	Open, randomized, comparative, multicenter study	Subjects aged between 12 and 15 years at the time of first vaccinationN = 300Mean age (range): 13.4 years (12–15 years)	Ambirix^TM2 doses at 0 and 6 monthsTwinrix pediatric^TM3 doses at 0, 1, and 6 monthsComparator: None	HAV: Enzymun (Boehringer Mannheim)^d Enzygnost (Boehringer)^e HBV: AUSAB RIA (Abbott)^c AUSAB EIA (Abbott)^f Equivalent validated in-house ELISA^f	Not reported	None
Moro Am J Obstet Gynecol 2014 [58]	US	Review of reports	Pregnant women who had received hepatitis A or combined hepatitis A and B vaccinationN = 35Maternal age, median (range): 28 years (19–39 years)	Twinrix^TMNumber of doses and schedule: NR	NA	None	VAERS is a passive surveillance system that may be prone to biased reporting and inconsistency in the quality and completeness of reports.VAERS generally cannot determine whether a vaccine caused an AE.VAERS does not collect data on the number of individuals vaccinated; therefore, it is not possible to calculate incidence or prevalence of AE.
Nothdurft Vaccine 2002 [37]	Germany, UK	Randomized. multicenter study	Healthy subjects with normal liver function test, seronegative for anti-HAV, anti-HBs, and anti-HBc, and none had previously been vaccinated against HA or HBN = 479 (239 subjects received Twinrix^TM)Mean age (range): Twinrix^TM: 24.9 years (18–45 years) Havrix^TM+ Engerix-B^TM: 27.0 years (18–48 years)	Twinrix^TM4 doses at 0,7,21 days and 12 monthsComparator: Havrix^TM+ Engerix-B^TM2 and 4 doses at 0 (7, 21) days, and 12 months	HAV: Enzymun ELISA (Boehringer Mannheim)^dHBV: AUSAB (Abbott)^c	Not reported	None
Ostergaard Vaccine 2012 [39]	Denmark, Sweden	Phase III, open, randomized controlled study	Healthy children who previously completed routine childhood vaccinationsN = 611Mean age (SD; range): M-TT + HAB: 14.3 years (1.89; 11–17) HAB: 14.3 years (1.94; 11–17)	Twinrix^TM (Pediatric or Adult, depending on age)3 doses at 0, 1, and 6 monthsComparator: MenACWY-TT1 dose at 0 months	HAV: Enzygnost ELISA (DADE Behring)^eHBV: In-house developed anti-HBs ELISA^a	GSK	None
Pedersen J Adolesc Health 2012 [40]	Canada, Denmark, Hungary, Sweden	Randomized, open, controlled, parallel group study	Healthy girlsN = 813Mean age (SD): HPV+HAB: 11.2 years (2.04) HAB: 11.2 years (1.99)	Twinrix pediatric^TM3 doses at 0, 1, and 6 monthsComparator: Cervarix^TM3 doses at 0, 1, and 6 months	HAV: Enzygnost ELISA (DADE Behring)^eHBV: HBs assay developed by GSK Biologicals^f Axsym Core (Abbott)^a	GSK	None
Ramonet Arch Med Res 2002 [51]	Argentina, Brazil, Mexico	Randomized study	Healthy children and adolescentsN = 248 (168 subjects received Twinrix^TM)Age range: 4–20 years	Ambirix^TM2 doses at 0 and 6 monthsComparator: Havirx + Engerix-B^TM2 doses at 0 and 6 months	HAV: Enzymun (Boehringer Mannheim)^dHBV: AUSRIAII (Abbott)^c CORAB (Abbott)^c AUSAB (Abbott)^c	GSK	None
Rendi-Wagner Vaccine 2001 [26]	Austria	Uncontrolled study	Healthy adolescents and adults who were seeking pre-travel immunization adviceN = 1874 (990 subjects received Twinrix^TM)Mean age (range): 43.4 years (6–80)	Twinrix^TM3 doses at 0, 1, and 6–12 monthsComparator: Engerix-B^TM or Gen H-B-Vax3 doses at 0, 1, and 6–12 months	HAV: NAHBV: AUSAB EIA (Abbott)^c	Not reported	None
Rieger Int J Occup Med Environ Health 2004 [27]	Germany	Open, controlled, randomized, monocentric study with two parallel groups	Healthy subjectsN = 304 (152 subjects received Twinrix^TM)Mean age (SD): 29.0 years (7.84)	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: Vaqta+ Gen H-B-Vax2 and 3 doses at 0 (1), and 6 months	HAV: ETI-AB-HAVK-3 (DiaSorin)^bHBV: ETI-AB-AUK-3 (DiaSorin)^c ETI-AB-COREK-2 (DiaSorin)^a	GSK	None
Roberton Vaccine 2005 [41] Marshall Vaccine 2010 [10]	Australia, Belgium, Spain, Sweden	Randomized, open-label, multicenter study with follow-up	Healthy childrenN = 511 (Ambirix^TM: 255, Twinrix pediatric^TM: 256)Mean age (SD; range), years: 6.0 (3.1; 1–11)	Ambirix^TM2 doses at 0 and 6 monthsTwinrix pediatric^TM3 doses at 0, 1, and 6 monthsComparator: None	HAV: Enzygnost (DADE Behring)^eHBV: Axsym HBsAg (Abbott)^f Axsym Core (Abbott)^f AUSAB EIA (Abbott)^f In-house ELISA assay^f	Not reported	None
Thoelen Vaccine 1999 [11]	Belgium, Lithuania, the Netherlands, Spain, Switzerland	Review of six clinical trials	Healthy adultsN = 843Mean age (SD; range): 20.8 years (4.2; 17–60)	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: None	HAV: Enzymum (Boehringer Mannheim)^dHBV: Radioimmunoassay (Abbott)^c
Thompson Int J Infect Dis 1998 [34]	Australia	Double-blind randomized clinical study	Healthy adolescentsN = 160Mean age: 16.4 years	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: None	HAV: Modified HAVAB (Abbott)^d Enzymun ELISA (Boehringer Mannheim)^d HBV: AUSRIA II (Abbott)^c AUSAB (Abbott)^c CORAB (Abbott)^c	Not reported	None
Usonis Vaccine 2005 [52]	Estonia, Lithuania	Comparative study	Healthy infants born to mothers not known to be seropositive for HBsAg, hepatitis B antigen or anti-HBc antibodiesN = 90Mean age (range): Lithuania: 16.5 months (15–18) Estonia: 12.5 months (11–15)	Ambirix^TM2 doses at 0 and 6 monthsComparator: None	HAV: Enzymum (Boehringer)^d HBV: AUSAB (Abbott)^c Axsym (Abbott)^c CORAB (Abbott)^c	Not reported	None
Van Damme Pediatr Infect Dis J 2011 [53]	Belgium	Open-label single group primary study	Healthy subjects without history of hepatitis or vaccination against HABN = 232Mean age 10 years after primary vaccination (SD): 17 years (2.84)	Ambirix^TM2 doses at 0 and 6 monthsComparator: None	HAV: Enzygnost (DADE Behring)^eHBV: AUSAB EIA (Abbott)^f Equivalent validated in-house ELISA^f	GSK	None
Van Damme J Med Virol 2001 [42] Diaz-Mitoma Vaccine 2008 [43]	Canada	Open study and a double-blind randomized study	Healthy childrenN = 166Age range: 1–15 years	Twinrix pediatricTM3 doses at 0, 1, and 6 monthsComparator: None	HAV: Enzymun (Boehringer Mannheim)^d Enzygnost (DADE Behring)^e HBV: AUSAB RIA (Abbott)^c AUSAB EIA (Abbott)^f	GSK	None
Van Der Wielen Vaccine 2006 [28] Chlibek J Travel Med 2011 [29]	Belgium, Czech Republic, Germany	Open, randomized, parallel group trial	Subjects seronegative for anti-HBs antibodies, anti-HBc antibodies, anti-HAV and HBsAgN = 596 (199 receiving Twinrix^TM)Mean age at first dose (SD; range): 55.2 years (9.6; 41–81)	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: Havrix^TM + Engerix-B^TM/Vaqta + HB-VAX-PRO2 and 3 doses at 0 (1), and 6 months	HAV: Enzygnost (DADE Behring)^eHBV: AUSAB (Abbott)^f	GSK	None
Van Der Wielen Pediatr Infect Dis J 2000 [54]	Belgium	Open, single center study	Healthy children/adolescentsN = 236Mean age: <6 years: 4.2 years ≥6 years: 9.1 years	Ambirix^TM2 doses at 0 and 6 monthsComparator: None	HAV: Enzymun (Boehringer Mannheim)^dHBV: AUSAB RIA (Abbott)^c CORAB (Abbott)^c AUSRIAII (Abbott)^c	Not reported	None
Van Herck Travel Med Infect Dis 2007 [30] Van Damme J Med Virol 2012 [14]	Belgium	Follow up of two double-blind, randomized trials	Healthy adultsN = 223 (Center 1: 116, Center 2: 107)Range (primary studies): 17–39 years and 17–43 years	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: None	HAV: Enzymun ELISA (Boehringer Mannheim)^d Enzygnost kit (DADE Behring)^e HBV: AUSAB RIA (Abbott)^c AUSAB EIA (Abbott)^f	GSK	None
Vilella Vaccine 2005 [56]	Spain	Prospective observational study	Subjects traveling to hepatitis A and hepatitis B highly endemic areas, who were candidates to receive HAB vaccineN = 998Mean age (SD; range): 23 years (4.5; 11–54)	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: None	HAV: NAHBV: NA	GSK	None
Williams Vaccine 2012 [31]	US	Outbreak study	Residents of nursing facilitiesN = 209Age range: 45–101 years	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: None	HAV: NAHBV: Monolisa (Bio-Rad) GS HbsAg EIA 3.0 (Bio-Rad) Vitros aHBc (Othro-Clinical diagnostics) Vitros HBcM (Othro-Clinical diagnostics) Vitros HbsAg (Othro-Clinical diagnostics) Vitros aHBs (Othro-Clinical diagnostics)	Not reported	Population not necessarily representative of all older adults, older persons with diabetes, or other long-term care facility residents -It is possible that some of the residents that were categorized as susceptible to HBV based on serologic results might have received HB vaccine in the past and either did not achieve a primary response or had antibody levels wane over time; such residents might be expected to have a more vigorous response to re-vaccination, which would have potentially increased the proportion who achieved seroprotection in this study
Wolters Hum Vaccin 2009 [32]	Germany	Multicenter trial with prospective and retrospective cohort	Prospective: Seronegative subjectsRetrospective: Subjects who had been vaccinated three times in the pastN = 422Mean age (range): Prospective: 38.9 years (18–79) Retrospective: 39.9 years (16–75)	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: None	HAV: Enzygnost (DADE Behring)^bHBV: Enzygnost (DADE Behring)^g Architect i2000SR (Abbott)^g	Not reported	Anti-HAV antibody concentration was measured only up to 80 IU/l The 4–8 week interval for antibody control was not strictly adhered to (might be especially problematic for HBV-low responders)
Wolters Vaccine 2003 [33]	Germany	Retrospective study	Patients vaccinated following manufacturer recommendationsN = 104Mean age (range): 54 years (17–84)	Twinrix^TM3 doses at 0, 1, and 6 monthsComparator: None	HAV: Axsym HAVAB 2.0 (Abbott)^bHBV: Axsym AUSAB II (Abbott)^g	Not reported	- Relatively old study population
Woo Vaccine 2006 [57]	Worldwide	Passive surveillance study	Recipients of Twinrix for whom a report of possible AE after vaccinated was received by VAERSN = 305 reportsMinimum age: 2 years	Twinrix^TMNumber of doses and schedule: NR	NA	None	Underreporting, incomplete information in many reports, inadequate data regarding the number of doses administered, and lack of direct and unbiased comparison group

CI: Confidence interval; EIA: Enzyme immunoassay; ELISA: Enzyme-linked immunosorbent assay; HAB: Hepatitis A and B; HAV: Hepatitis A virus; HBc: Hepatitis B core antigen; HBs: Hepatitis B surface antigen; HBV: Hepatitis B virus; HCV: Hepatitis C virus; HIV: Human immunodeficiency virus; HPV: Human papillomavirus; M-TT: Tetravalent meningococcal conjugate vaccine coupled to tetanus toxoid; NA: Not applicable; NR: Not reported; RIA:Radioimmunoassay; SD: Standard deviation.

*Study design not reported in the article. Design defined by Pallas.

^aCut-off: NR.

^bCut-off: 20 (m)IU/(m)l.

^cCut-off: 1 (m)IU/(m)l.

^dCut-off: 33 (m)IU/(m)l.

^eCut-off: 15 (m)IU/(m)l.

^fCut-off: 3.3 (m)IU/(m)l.

^gCut-off: 10 (m)IU/(m)l.

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