Safety profile comparison of chimeric live attenuated and Vero cell-derived inactivated Japanese encephalitis vaccines through an active surveillance system in Australia

Figures & data

Figure 1. Flowchart of the selection of patients for comparison of local adverse events following immunization between Japanese encephalitis vaccines.

Table 1. Characteristics of patients and adverse events following immunization by type of Japanese encephalitis vaccine received

	Imojev N= 1855 n (%)	JEspect N = 901 n (%)	p-Value
Female patients	963 (51.9)	486 (53.9)	.318
Age group			<.001
<5 years	54 (3.0)	10 (1.1)
5 to 15 years	129 (7.0)	55 (6.1)
16 to 30 years	577 (31.1)	368 (40.8)
31 to 50 years	613 (33.1)	251 (27.9)
>50 years	482 (26.0)	217 (24.1)
Number of other vaccines received on the same day			.526
0	429 (23.1)	208 (23.1)
1	621 (33.5)	295 (32.7)
2	420 (22.6)	225 (25.0)
≥3	385 (20.8)	173 (19.2)
Overall AEFI	140 (7.6)	53 (5.9)	.108
Systemic AEFI	56 (3.0)	21 (2.3)	.304
Tiredness	42 (2.3)	17 (1.9)	.521
Headache	31 (1.7)	10 (1.1)	.254
Fever	16 (0.9)	8 (0.9)	.946
Irritability	13 (0.7)	4 (0.4)	.419
Sleep disturbance	11 (0.6)	3 (0.3)	.368
Diarrhea	10 (0.5)	4 (0.4)	.742
Vomiting	2 (0.1)	2 (0.2)	.460
Rigors	1 (0.1)	1 (0.1)	.602
Convulsions	0 (0.0)	0 (0.0)	-
Hypotonia	0 (0.0)	0 (0.0)	-
Local AEFI	37 (2.0)	15 (1.7)	.551
Pain	26 (1.4)	12 (1.3)	.883
Swelling	29 (1.6)	6 (0.7)	.048
Rash	5 (0.3)	5 (0.6)	.242
Other reactions	15 (0.8)	6 (0.7)	.686
Unspecified type of AEFI	74 (4.0)	29 (3.2)	.317

Unspecified type of AEFI refers when the patient indicated that he/she presented an AEFI, but did not specify the symptom/sign (e.g. tiredness, pain).

None of ‘Other reactions’ were severe e.g. anaphylaxis.

AEFI adverse event following immunization.

Figure 2. Percentage of patients who reported overall, systemic, and local adverse events following immunization (AEFIs) by the type of Japanese encephalitis vaccine received.

103 patients did not specify the type AEFI. The percentage of patients with unspecified AEFI with Imojev (4.0%) and JEspect (3.2%) were not different (p-value = 0.317).

Table 2. Univariate and multivariable logistic regression models for predictors of overall, local, and systemic adverse events following Japanese encephalitis immunization

	Overall AEFI		Systemic AEFI		Local AEFI
	Univariate OR (95% CI)	Multivariable OR (95% CI)	Univariate OR (95% CI)	Multivariable OR (95% CI)	Univariate OR (95% CI)	Multivariable OR (95% CI)
Vaccine type
JEspect (reference)	1	1	1	1	1	1
Imojev	1.30 (0.94–1.81)	1.27 (0.91–1.77)	1.30 (0.78–2.16)	1.23 (0.74–2.06)	1.20 (0.66–2.20)	1.20 (0.65–2.22)
Age group
<5 years	2.27 (1.06–4.88)	2.39 (1.10–5.19)	1.96 (0.66–5.85)	2.01 (0.66–6.09)	3.08 (0.83–11.32)	4.13 (1.08–15.74)
5 to 15 years	0.80 (0.40–1.61)	0.83 (0.41–1.68)	0.32 (0.08–1.38)	0.33 (0.08–1.42)	1.04 (0.29–3.75)	1.14 (0.31–4.19)
16 to 30 years	1.01 (0.68–1.49)	0.98 (0.66–1.45)	0.70 (0.39–1.27)	0.66 (0.36–1.20)	1.35 (0.65–2.85)	1.22 (0.58–2.60)
31 to 50 years	1.09 (0.74–1.62)	1.08 (0.73–1.61)	0.91 (0.52–1.62)	0.92 (0.52–1.63)	1.11 (0.51–2.43)	1.06 (0.48–2.34)
>50 years (reference)	1	1	1	1	1	1
Sex
Male (reference)	1	-	1	-	1	-
Female	1.64 (1.21–2.22)	-	2.16 (1.32–3.54)	-	3.43 (1.76–6.70)	-
Number of other vaccines received
0 (reference)	1	-	1	-	1	-
1	1.34 (0.89–2.02)	-	1.40 (0.75–2.62)	-	2.53 (0.93–6.84)	-
2	0.90 (0.55–1.46)	-	0.72 (0.33–1.58)	-	1.99 (0.68–5.86)	-
≥3	1.67 (1.08–2.58)	-	1.62 (0.83–3.18)	-	4.46 (1.65–12.01)	-
Interaction between sex and number of other vaccines received
Male and no other vaccine (reference)	-	1	-	1	-	1
Male and 1 additional vaccine	-	1.00 (0.53–1.91)	-	1.05 (0.39–2.80)	-	1.19 (0.28–5.03)
Male and 2 additional vaccine	-	0.69 (0.33–1.44)	-	0.37 (0.09–1.47)	-	0.29 (0.03–2.87)
Male and ≥3 additional vaccine	-	0.82 (0.40–1.69)	-	0.40 (0.10–1.56)	-	0.67 (0.11–4.12)
Female and no other vaccine	-	0.89 (0.46–1.75)	-	0.89 (0.32–2.50)	-	0.50 (0.08–3.01)
Female and 1 additional vaccine	-	1.69 (0.73–3.94)	-	1.76 (0.49–6.36)	-	4.03 (0.50–32.18)
Female and 2 additional vaccines	-	1.79 (0.68–4.71)	-	3.38 (0.63–18.27)	-	19.68 (1.26–306.09)
Female and ≥3 additionalvaccines	-	3.62 (1.45–9.05)	-	8.75 (1.75–43.65)	-	21.06 (2.06–215.69)

AEFI adverse event following immunization; OR odds ratio; CI confidence interval.

Figure 3. Percentage of patients who reported adverse events following Japanese encephalitis immunization by sex and other vaccines received on the same day.

DPT diphtheria, pertussis, and tetanus; MMR measles, mumps, and rubella; HepA hepatitis A; HepB hepatitis B.