Persistence of immunity in healthy adults aged ≥50 years primed with a hepatitis B vaccine 3 years previously

Figures & data

Figure 1. Disposition of study participants

Table 1. Demographics of study population

	Primary vaccination
	HBvaxPRO®N = 96	Engerix B™ N = 108	Total N = 204
Age at vaccination (y)
Mean (SD)	63.8 (7.3)	63.6 (6.7)	63.7 (7.0)
Median	63	63	63
Minimum–maximum	53–85	54–83	53–85
Sex, n (%)
Men	48 (50.0)	45 (41.7)	93 (45.6)
Women	48 (50.0)	63 (58.3)	111 (54.4)
Primary series: dose 3 to challenge dose (y)
Mean (SD)	3.3 (0.1)	3.3 (0.1)	3.3 (0.1)
Median	3.3	3.3	3.3
Range	3.1–3.5	3.1–3.5	3.1–3.5

SD: standard deviation

Table 2. Individuals with an anti-HBs titer ≥10 mIU/mL (primary endpoint) and geometric mean titers pre- and 1 month post-challenge with HBvaxPRO® (per protocol set)

Primary vaccination	HBvaxPRO®N = 88	Engerix B™N = 103
	Pre-challenge	Post-challenge	Pre-challenge	Post-challenge
N	88	88	102	103
Missing	0	0	1	0
Anti-HBs titers ≥10 mIU/mL
n (%)	40 (45.5)	75 (85.2)	60 (58.8)	91 (88.3)
[95% CI]	[34.8; 56.4]	[76.1; 91.9]	[48.6; 68.5]	[80.5; 93.8]
GMT
Mean	12.3	957.4	24.1	1,497.60
[95% CI]	[8.3; 18.4]	[470.5; 1,948.4]	[15.6; 37.3]	[823.8; 2,722.5]

CI: confidence interval, GMT: geometric mean titers.

Table 3. Individuals with an anti-HBs titer ≥10mIU/mL pre- and 1 month post-challenge with HBvaxPRO®(exploratory analyses, individual subgroups) (per protocol set)

Primary vaccination impact	HBvaxPRO®n = 88	Engerix B™n = 102
Anti-HBs titer after the primary vaccination series	Anti-HBs titer before the pre-challenge dose	Pre-challenge	Post-challenge	Pre-challenge	Post-challenge
		N	N	N	N
		n (%)	n (%)	n (%)	n (%)
		[95% CI]	[95% CI]	[95% CI]	[95% CI]
		18	18	12	12
<10mIU/mL	Any	1 (5.6)	9 (50.0)	0 (0.0)	2 (16.7)
		[0.1; 27.3]	[26.0; 74.0]	[0; 26.5]	[2.1; 48.4]
		39	39	60	60
≥10mIU/mL	≥10mIU/mL	39 (100)	39 (100)	60 (100)	60 (100)
		[91.0; 100]	[91.0; 100]	[94.0; 100]	[94.0; 100]
		31	31	30	30
≥10 mIU/mL	<10mIU/mL	0	27 (87.1)	0	28 (93.3)
		[0; 11.2]	[70.2; 96.4]	[0; 11.6]	[77.9; 99.2]

CI: confidence interval.

* One subject was not tested at visit 1 and then was not included in this analysis.

^† One subject had a pre-challenge dose titer above 10 mIU/mL (57.8 mIU/mL), although the subject was not seroprotected after dose 3 of HBVaxPro® in the primary vaccination series (anti-HBs titer of <5mIU/mL).

Table 4. Summary of safety analysis (SAS)

	Total population (N = 203)n (%)
With no AEs	116 (57.1)
With 1 or more AEs (Day 1 to Day 15)	87 (42.9)
Injection site AE	66 (32.5)
Systemic AE	46 (22.7)
With a vaccine-related AE (Day 1 to Day 15)	75 (36.9)
Injection site AE	66 (32.5)
Systemic AE	20 (9.9)
With SAE (entire study period)	1 (0.5)
With vaccine-related SAE	0
Deaths	0
Discontinued due to an AE (entire study period)	0
With injection-site AE from Day 1 to Day 15
Solicited injection-site AE	64 (31.5)
Pain	58 (28.6)
Erythema	11 (5.4)
Swelling	10 (4.9)
Unsolicited injection-site AE	7 (3.4)
Pruritus	4 (2.0)
Erythema	1 (0.5)
Hematoma	1 (0.5)
Induration	1 (0.5)
Paresthesia	1 (0.5)
Swelling	1 (0.5)
With systemic AE from Day 1 to Day 15
All systemic AEs	46 (22.7)
Vaccine-related systemic AEs	20 (9.9)

AE, adverse event; SAE, serious adverse event;

* may include injection site erythema, swelling and pain from Day 6 to Day 15.