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Immunogenicity and reactogenicity of a combined high dose hepatitis A and hepatitis B vaccine, compared to that of Twinrix™ in healthy Indian children
Vaccine 20 (2002) 2102–2106
Immunogenicity and reactogenicity of a combined high dose hepatitis A and hepatitis B vaccine, compared to that of TwinrixTM in healthy Indian children Rajkumar C. Guptan a , Varsha Thakur a , Assad Safary b , Shiv K. Sarin a,∗ a
Department of Gastroenterology, GB Pant Hospital, New Delhi, India b GlaxoSmithKline Biologicals, Rixensart, Belgium
Received 17 August 2001; received in revised form 6 January 2002; accepted 11 January 2002
Abstract Background and aims: Hepatitis A virus (HAV) and hepatitis B virus (HBV) are vaccine preventable important childhood acquired infectious diseases in developing countries. In the changing epidemiology of HAV, the utility of such a vaccine in India needs urgent attention. Further, the efficacy of two versus three dose schedule needs to be assessed to improve compliance. Subjects and methods: One hundred healthy school children, aged 1–15 years were recruited in a randomised open study to receive either vaccination schedule: Group I: combined high-dose hepatitis A and B vaccine to be administered on a 0, 6 month schedule intramuscularly; Group II: to be administered on 0, 1, 6 month TwinrixTM (GlaxoSmithKline Biologicals, Rixensart, Belgium) schedule intramuscularly. The seroconversion (≥1 MIU/ml for anti-HBs antibodies and ≥33 MIU/ml for anti-HAV antibodies) and seroprotection (anti-HBs ≥10 MIU/ml after the third dose of vaccine) rates were determined at months 1, 2, and 7. Results: The mean age and gender was similar between groups: 7.9 ± 2.6 years (range 3–15 years). At month 7 all subjects (100%) in both groups were seropositive for anti-HAV antibodies, Group I had higher anti-HAV titres at months 1 or 2 compared to Group II (P = 0.025, P = 0.040). Group II developed higher seroprotection rates (month 2, P = 0.002, month 6, P = 0.003) compared to Group I and higher titres (month 2, P = 0.001, month 6 P = 0.001) compared to Group I. At month 7, the geometric mean titres (GMTs) were comparable between groups and seroprotection reached 100% in both the groups. The incidence of any symptom per dose analysis reported during a 4-day follow-up period was significantly higher in Group I, 53% (52/98) of the documented doses compared to 37% (54/146) in Group II (P = 0.018). Conclusion: TwinrixTM vaccine is safe and highly immunogenic in Indian children. Further study of the high dose vaccine would determine if its two dose regimen is a feasible advantage. © 2002 Elsevier Science Ltd. All rights reserved. Keywords: Immunogenicity; TwinrixTM ; Hepatitis
1. Introduction Hepatitis A virus (HAV), is an important cause of childhood acquired acute hepatitis and liver failure in developing countries [1,2]. The spread of HAV is primarily by orofaecal route, but is rarely transmitted sexually or parenterally [3,4]. Epidemiological studies have also demonstrated that HAV exposure increases with low hygiene and increasing age [5]. The severity of hepatitis A is also known to be increased in unexposed young adults with high case fatality rates [6]. With the availability of safe inactivated HAV vaccine, the epidemiological pattern of HAV in children and high-risk populations can be greatly influenced [7]. ∗
Corresponding author. Tel.: +91-11-3232013; fax: +91-11-3239442. E-mail address: [email protected] (S.K. Sarin).
Hepatitis B virus (HBV), is also an important cause of hepatitis in children, in developing countries [8–10]. The risk of HBV infection becoming chronic has an inverse relation to age. The chronicity of HBV infection is around 90% if it is acquired below 1 year of age [11]. In countries like India with relatively high HBV prevalence, perinatal transmission of HBV is an important public health problem [8,12,13]. The most comprehensive approach to eliminate chronic HBV infection and related liver cancer has been the strategy of universal and high-risk group immunisation [14,15]. The two important causes of childhood acquired hepatitis, hepatitis A and B, can be prevented by vaccination. The incorporation of these two vaccines in the expanded program of immunisation (EPI) for children would have problems of compliance, even in the developed countries, due to the high cost and increased number of injections.
0264-410X/02/$ – see front matter © 2002 Elsevier Science Ltd. All rights reserved. PII: S 0 2 6 4 - 4 1 0 X ( 0 2 ) 0 0 0 4 6 - 4
R.C. Guptan et al. / Vaccine 20 (2002) 2102–2106
In view of this, a combined HAV and HBV vaccine has been developed recently [16]. A randomised open trial was initiated in healthy school children in India to evaluate the immunogenicity reactogenicity of a high combined hepatitis A and B vaccine compared to that of TwinrixTM .
2. Subjects and methods An open randomised study was initiated in September 1997 after prior approval of the Institutional Ethical Committee. Healthy school children were recruited in the study if they fulfilled the following inclusion criteria: age between 1 and 15 years, good physical condition as assessed by clinical-biochemical examination, informed consent from parents. The following exclusion criteria were followed: positive titres for anti-HAV, anti-HBs, anti-HBc, HBsAg, AST/ALT >1.5 times normal, history of significant hematologic, hepatic, renal, cardiac or respiratory disease. Hepatomegaly or features of chronic or acute hepatitis, chronic drug therapy, immunosuppressive or immunomodulatory therapy, history of allergic syndrome to vaccines, simultaneous participation in any other clinical trial, previous vaccination against hepatitis A or B. 2.1. Methodology of the trial This was undertaken according to good clinical practice (GCP) and quality of subject data recording and adverse experience monitoring was audited in-house and by independent regulatory compliance monitors. Adherence to the protocol requirements and verification of data generation accuracy was achieved through monitoring visits and methodologies detailed per standard operating procedures (SOPS). 2.2. Study design One hundred children fulfilled the inclusion criteria and were enrolled in the study. By computer generated random numbers they were allotted subject numbers to be included in one of the following treatment schedules. 2.2.1. Group I Group I received a combined high dose hepatitis A and B (HAB) vaccine containing per dose (0.5 ml volume) 720 ELISA units (EL.U) of inactivated HAV-HM 175 strain + 20 mcg recombinant hepatitis B surface antigen (HBsAg) administered according to a two-dose schedule (0, 6 months). 2.2.2. Group II Group II received TwinrixTM containing per 0.5 ml dose 360 EL.U inactivated HAV HM 175 strain + 10 mcg recombinant HBsAg administered according to a three-dose schedule (0, 1, 6 months).
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2.3. Criteria for evaluation Immunogenicity: Seroconversion rates for hepatitis A and seroprotection rates for hepatitis B at month 7. Seroconversion: This was defined as the appearance of antibodies (≥1 MIU/ml for anti-HBs antibodies and, ≥33 MIU/ml anti-HAV antibodies) in previously sero negative subjects. Seroprotection: This was defined for hepatitis B vaccine only and for anti-HBs levels ≥10 MIU/ml after the third dose of vaccine. Reactogenicity: This was defined as the nature and incidence of reaction after each dose of vaccine. After each vaccine dose local and general symptoms, including body temperature, were recorded by the subject or his/her parent or guardian on diary cards. A qualified nurse and co-investigator did site visits for three consecutive days post-vaccination, then every month, to monitor the subjects. Symptoms were graded as either absent, grade 1 (easily tolerated), grade 2 (sufficiently discomforting to interfere with normal daily activity) or grade 3 (prevented normal daily activity). The investigator assessed the relationship to vaccination of solicited and unsolicited symptoms at each subsequent visit of the vaccine. Any serious adverse event, including any case of hospitalization, was to be reported by the investigator to the sponsor within 24 hours of occurrence. 2.4. Statistical analysis Mean ages and gender were compared between groups using two way ANOVA; ratio of males to females between groups was compared using Fisher’s exact test. Anti-HAV and anti-HBs geometric mean titres (GMTs) were determined by taking the anti-log of the mean log titre transformations. GMTs were compared between groups at all time points (1, 2, 6, and 7 months) using Wilcoxon’s test. Anti-HAV seropositivity rates and anti-HBs seroprotection rates between groups, and incidence of symptoms between groups were also compared at all time points using Fisher’s exact test.
3. Results 3.1. Subjects Of the 100 children enrolled, 96 completed the vaccination trial. None of the four drop outs, two from each group, were due to adverse event. The demographic profiles of the two groups of children were comparable (Table 1). The mean age and gender was similar between the groups. The mean age of the total cohort was 7.9 ± 2.6 years (range 3–15 years). All the children were of Asian Indian origin.
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and the seroprotection rates reached 100% in both the groups.
Table 1 Demographic profile of study subjects Male
Female
Total
Range (years)
Group I (n) Mean age
29 8.2 ± 2.7
21 8.0 ± 2.7
50 8.2 ± 2.7
3–14
Group II (n) Mean age
27 7.7 ± 2.8
23 7.4 ± 2.2
50 7.6 ± 2.5
3–15
All (n) All mean
56 8 ± 2.4
44 7.7 ± 2.5
100 7.9 ± 2.6
3–15
3.2. Immunogenicity 3.2.1. Anti-HAV antibody response One month after the full vaccination course (at month 7) all subjects (100%) in both groups were seropositive for anti-HAV antibodies. Group I had significantly higher anti-HAV GMT at month 1 compared to Group II (P = 0.025, Wilcoxon’s test). While it reached comparable levels at month levels at month 7, the GMTs in mIU/ml Group I reached a peak of 6916 compared to 4865 mIU/ml in Group II. [None of the subjects in the study group developed jaundice or biochemical evidence of acute viral hepatitis during the course of seroconversion]. These results are presented in Table 2. 3.2.2. Anti-HBs antibody response One month after the full vaccination course, all subjects (100%) were seroprotected for anti-HBs antibodies (Table 3). It was interesting to note that in Group II a significantly higher number of subjects developed seroprotection at months 2 and 6 (P = 0.002, P = 0.003) compared to Group I, Fisher’s exact test. When quantitative titres were done, GMT of anti-HBs was also significantly higher in Group II at month 2 (P = 0.001) and month 6 (P = 0.001) compared to Group I. At month 7, the GMTs were comparable between the groups
3.3. Reactogenicity The overall incidence of any symptom per dose analysis reported during the 4-day follow-up period was significantly higher in Group I (Table 4): 53% (52 of 98) of the documented doses in Group I compared to 37% (54 of 146) in Group II (P = 0.018, Fisher’s exact test). 3.3.1. Local symptoms No grade 3 solicited local symptoms were reported, and all subjects with local symptoms recovered within 3–4 days. Soreness at injection site was the most frequently reported local symptom in both groups. Incidence of redness was seen in 10% (5/50) in Group I compared to 28% (14/50) in Group II (P = 0.04). 3.3.2. General symptoms No grade 3 general symptoms were reported. Low grade temperature (range 99–102 ◦ F) was the most prevalent general symptom in both groups; 28.6% (26/98) in Group I versus 19.9% (29/146) in Group II. 3.3.3. Unsolicited symptoms Unsolicited symptoms, i.e. those reported as ‘others’ or solicited complaints reported after the protocol specified follow-up period, were reported by 21 subjects (14 in Group I and 7 in Group II). Of these symptoms, three (12%) were local and 22 (88%) were general symptoms. Only five (20%) of these were found to be ‘possibly related’ to the vaccination (Table 5). 3.3.4. Serious adverse event One subject reputed a serious adverse event ‘possibly related” to the study vaccine. The event occurred in Group I and comprised low grade fever (100 ◦ F), redness at injection
Table 2 Post-vaccination seroconversion rates and GMTs of anti-HAV antibodies Group
Month
N
Seroconversion n (%)
95% CI LL
I
(97.9)a
GMT UL 424b
95% CI LL
UL
M1 M2 M6 M7
48 45 46 48
47 42 (93.3) 41 (89.1) 48 (100)
88.9 81.7 76.4 92.6
99.9 98.6 96.4 100
301 192 6916
279 187 120 4866
644 486 306 9830
M1 M2 M6 M7
47 48 48 48 –
37 46 41 42 –
64.3 85.7 72.2 92.6 –
89.3 99.5 93.9 100 –
295 514 245 4865 –
155 305 134 3229 –
560 867 449 7330 –
II
(78.7) (95.8) (85.4) (100)
M1, 2, 6, 7: month 1–7 post-vaccination; Group I, combined high dose HAV + HBV vaccine; N, number; Group II, TwinrixTM vaccine; GMT, geometric mean titre; 95% confidence interval. a Anti-HAV seroconversion rate statistically significantly higher in Group I at month 1 (P = 0.037), Fisher’s exact test. b Anti-HAV GMT statistically significantly higher in Group I, at month 1 (P = 0.02), Wilcoxon’s test.
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Table 3 Post-vaccination seroconversion, seroprotection and GMTs of anti-HBs antibodies Group
Month
N
Seroconversion n (%)
95% CI
Seroprotection n (%)
LL
UL
(72.4)a ,b
(63.8) (91.7) (97.4) (100)
95% CI
GMT
LL
UL
95% CI LL
UL
I
M1 M2 M6 M7
48 45 46 48
35 40 (88.9) 44 (95.7) 48 (100)
58.2 75.9 85.2 92.6
84.7 96.3 99.5 100
21 22 31 48
(43.8) (46.9) (67.4) (100)
29.5 33.7 52.0 92.6
58.8 64.2 80.5 100
13 12 20 3022
7 7 13 1760
22 19 31 5191
II
M1 M2 M6 M7
47 48 48 48
30 44 47 48
48.5 86.0 88.9 92.6
77.3 97.3 99.9 100
17 38 46 48
(36.2) (79.2)a (95.8)a (100)
22.7 65.0 85.7 92.6
51 89.5 99.9 100
14 88b 133b 5996b
6 46 72 3437
34 16 246 10458
Group I, combined high dose HAV + HBV vaccine; Group II, TwinrixTM vaccine; GMT, geometric mean titre; CI, confidence interval of 95%; M1, 2, 6, 7 month 1–7 post-vaccination. a Anti-HBs seroprotection rate statistically significantly higher in Group II at month 2, P = 0.002, month 6, P = 0.0003, (Fisher’s exact test). b Anti-HBs GMT statistically significantly higher in Group II at month 2, P = 0.001, month 6, P = 0.001 (Wilcoxon’s test).
Table 4 Incidence of local or general symptoms during post-vaccination period Group
N
All symptoms
Per dose analysis I II
98 146
52 (53.1%)a 54 (37.0%)
Per subject analysis I II
50 50
45 (90%) 41 (82%)
a Reactogenicity for all symptoms significantly higher in Group I compared to Group II (P = 0.018, Fisher’s exact test).
Table 5 Possibly related unsolicited symptoms WHO preferred term
Group I
Group II
Abdominal Pain Vomiting Pruritis
1 1 2 15 7 1 1 0 1 0 1
0 0 1 – 5 0 0 1 0 1
Coughing Pharyngitis Vomiting Pain abdomen Eye pain Earache Fever
site, abdominal pain and vomiting 2 days after the second dose of the vaccine. The child responded to the medication and recovered the following day.
4. Discussion The results of the present study clearly indicate the safety and satisfactory immure response of both vaccine regimens in children. One month after completion of the vaccination
course, almost 100% children became seropositive for HAV antibodies. This observation is similar to the immunogenicity for HAV vaccine reported after combined hepatitis A and B vaccine administration in young Europeans [17–20]. This result is also similar to the observation reported recently from China [21,22]. The seroconversion rate of 100% for HAV is also comparable to the seroconversion seen in relatively older Indian males taking HAV vaccine alone [23]. Both combined vaccines also achieved almost 100% seroprotection for HBV. This is similar to the observation with combined vaccine elsewhere [17–22]. Combination vaccines are not only known to minimise the number of doses required for universal vaccination, but they also increase compliance since less parental interventions are needed compared to what these individual vaccines would require. Moreover, studies have also demonstrated that HBV and HAV vaccines fare better when taken simultaneously or combined [24]. The complementary effect of the two viral antigens are not merely due to a local phenomenon due to activation of the cytokine pathways and macrophage activity [16], but also possibly due to stimulation of similar systemic pathways [25]. At completion of the study at month 7, rates of seroconversion and seroprotection were similar in both groups, the high dose as well as TwinrixTM . The GMTs of HAV were significantly higher in the first month after injection in the subjects who received the high dose (Group I). Subsequently, the GMTs became comparable at the end of the study. Similarly, the anti-HBs GMTs at month 2 were higher in Group II who received, however TwinrixTM , comparable with Group I at month 7. These results indicate that the immunogenicity of the high dose vaccination was comparable to TwinrixTM and that either schedule could be recommended. The results of the present study support the findings from recent European studies done in adult Grueb et al. [19], during which all subjects developed seroconversion for HAV and seroprotection for HBV at month 7. Adverse experiences
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were minimal in this adult population, even after high dose vaccine. In our study, one subject reported a serious adverse experience, possibly related to the vaccine. He reported to the investigators with pain abdomen, fever, vomiting 2 days after the second dose of the vaccine. However, he rapidly responded to medical treatment. It thus appears that increasing the dose of hepatitis A and B antigen increases the immunogenicity for HAV, but may enhance the reactogenicity in children. While earlier studies in India have reported that exposure to HAV below 5 years of age reached almost 90%, recent reports indicated that about 32% of children remained prone to develop acute hepatitis A, untill the age of 16 years [26]. This change in the epidemiology of HAV therefore cautions us to develop strategies to protect these adolescents and adults from hepatitis A. Since hepatitis B infection is most often acquired in India in the early childhood, it would be worthwhile to evaluate a strategy where a combined vaccine could decrease the incidence of both viral infections. Economic considerations would need to be carefully considered in a developing country like India. Furthermore, TwinrixTM vaccine not only demonstrates high immunogenicity but is also very safe and can be incorporated in the EPI programs. In conclusion, this combined vaccine regimens against hepatitis A and B were highly immunogenic in Indian children. They provide the advantage of fewer injections, lower cost, and possibility of easy incorporation within the present immunisation programs. References [1] Arora NK, Nanda SK, Gulati S, Ansari H, et al. Acute viral hepatitis types E, A and B singly or in combination in acute liver failure in children in north India. J Med Virol 1996;48(3):215–21. [2] Chadha MS, Chitambar SD, Naseem JS, Arankalle VA. Exposure of Indian children to hepatitis A virus and vaccination age. Ind J Med Res 1999;109:11–5. [3] Centers for Disease Control. Hepatitis A among drug abusers. MMWR 1998;37:297. [4] Centre for Disease control. Hepatatis A among homosexuals in United States, Canada and Australia. MMWR 1992;41:155–64. [5] Kiyohara T, Satoh T, Yamamoto H, Totsuka A, Moritsugn Y. The latest sero-epidemiological pattern of hepatitis A in Japan. J Med Sci Biol 1997;50:123–31. [6] Berge JJ, Drennan DA, Jacobs RJ, Jakins A, et al. The cost of hepatitis A infection in American adolescents and adults in 1997. Hepatology 2000;31:469–73. [7] Bader TF. Hepatitis A vaccine. Am J Gastroenterol 1995;91:217–22. [8] Nayak NC, Panda SK, Zuckerman AJ, et al. Dynamics and impact of perinatal transmission of hepatitis B virus in North India. J Med Viral 1987;21:137–45. [9] Chen HL, Chang MH, Ni YH, Hsu HY, Lee CY, Chen DS, et al. Seroepidemiology of hepatitis B virus infection and children. JAMA 1996;276:906–8.
[10] Fuji Sawa T, Komatsu H, Inui A, Sogo T, et al. Long-term outcome of chronic hepatitis B in adolescents or young adults in follow up from childhood. J Pedrat Gastroenterol Nutr 2000;30:201– 6. [11] McMohan BJ, Alward WLM, Hart DO, et al. Acute hepatitis B virus infection relation of age to clinical expression of disease and subsequent development of the carrier state. J Infet Dis 1985;151:563–99. [12] Xu ZY, Liu CB, Francis DP, et al. Prevention of perinatal acquisition of hepatitis B virus carriage using vaccine: preliminary report of a randomised double blind placebo controlled and comparative trial. Paediatrics 1985;7:713–5. [13] Guptan RC, Thakur V, Sarin SK. Hepatitis B in high risk groups in India. In: Sarin SK, Singal AK, editors. Hepatitis B in India: problems and prevention. Ist ed. Delhi: CBS Publishers, 1996. p. 39– 50. [14] Centers for Disease Control. Hepatitis B virus, a comprehensive strategy for eliminating transmission in the United States through universal childhood vaccination. Recommendation of the Immunisation Practices Advisory Committee (ACIP). MMWR 1991;40:13–7. [15] Poovorawan Y, Sanpavat S, Pong Punlert W, et al. Long-term efficacy of hepatitis B vaccine in infants born to HBeAg positive mother: effect of vaccination with a yeast derived vaccine according to different schedules with and without concomitant hepatitis B immunoglobulin. Pediatr Inf Dis J 1992;11:816–8. [16] Van Damme P, Thoelen S, Cramm M, Safary A, Mehens A. Reactogenicity and immunogenicity of a combined hepatitis A and B vaccine in healthy adults. Viral Hep Liver Dis 1994;514–6. [17] Bruguera M, Bayas JM, Vilella A, Tural C, Gonzale A, et al. Immunogenicity and reactogenicity of a combined hepatitis A and B vaccine in young adults. Vaccine 1996;14:1407–11. [18] Knoll A, Holtentrager B, Kain ZJ, Bretschneider B, Jilg W. Immunogenicity of a combined hepatitis A and B vaccine in healthy young adults. Vaccine 2000;18:2029–32. [19] Greub G, Genton B, Safary A, Thoelen S, Frei PC. Comparison of the reactogenicity and immunogenicity of a two injection combined high dose hepatitis A and hepatitis B vaccine to those of TwinrixTM . Vaccine 2001;19:1113–7. [20] Herck KV, Damme PV, Callard F, Thoelen S. Two dose combined vaccination against hepatitis A and B in healthy subjects aged 11–18 years. Scand J Gastroenterol 1999;12:1236–40. [21] Tsai IJ, Chang MH, Chen HL, Ni YH, Lee PT, Chin TY, et al. Immunogenicity and reactogenicity of the combined hepatitis A and B vaccine in young adults. Vaccine 2001;19:437–41. [22] Lee SD, Chan CY, Yu MI, Wang YJ, Chang FY, Lo KJ, et al. A two dose combined hepatitis A and B vaccine in Chinese youngster. J Med Virol 1999;59:1–4. [23] Das K, Jain A, Gupta RK, Kar P. Immunogenicity and reactogenicity of an inactivated hepatitis A vaccine in Indian adults. Nat Med J Ind 1999;12:268–9. [24] Czeschinski PA, Binding N, Witting U. Hepatitis A and hepatitis B vaccinations: immunogenicity of combined vaccine and of simultaneously or separately applied single vaccines. Vaccine 2000;18:1074–80. [25] Ambrosh F, Niedermann G, Andre FE, Delem A, Gregor H, Hafmann H, et al. Clinical and immunological investigation of a new combined hepatitis A and hepatitis B vaccine. J Med Virol 1994;44:452–6. [26] Thakur V, Guptan RC, Bagga S, Safary A, Sarin SK. Prevalence of hepatitis A antibodies in children in India. Ind J Gastroenterol 1998;17:27.
Immunogenicity and reactogenicity of a combined high dose hepatitis A and hepatitis B vaccine, compared to that of TwinrixTM in healthy Indian children Rajkumar C. Guptan a , Varsha Thakur a , Assad Safary b , Shiv K. Sarin a,∗ a
Department of Gastroenterology, GB Pant Hospital, New Delhi, India b GlaxoSmithKline Biologicals, Rixensart, Belgium
Received 17 August 2001; received in revised form 6 January 2002; accepted 11 January 2002
Abstract Background and aims: Hepatitis A virus (HAV) and hepatitis B virus (HBV) are vaccine preventable important childhood acquired infectious diseases in developing countries. In the changing epidemiology of HAV, the utility of such a vaccine in India needs urgent attention. Further, the efficacy of two versus three dose schedule needs to be assessed to improve compliance. Subjects and methods: One hundred healthy school children, aged 1–15 years were recruited in a randomised open study to receive either vaccination schedule: Group I: combined high-dose hepatitis A and B vaccine to be administered on a 0, 6 month schedule intramuscularly; Group II: to be administered on 0, 1, 6 month TwinrixTM (GlaxoSmithKline Biologicals, Rixensart, Belgium) schedule intramuscularly. The seroconversion (≥1 MIU/ml for anti-HBs antibodies and ≥33 MIU/ml for anti-HAV antibodies) and seroprotection (anti-HBs ≥10 MIU/ml after the third dose of vaccine) rates were determined at months 1, 2, and 7. Results: The mean age and gender was similar between groups: 7.9 ± 2.6 years (range 3–15 years). At month 7 all subjects (100%) in both groups were seropositive for anti-HAV antibodies, Group I had higher anti-HAV titres at months 1 or 2 compared to Group II (P = 0.025, P = 0.040). Group II developed higher seroprotection rates (month 2, P = 0.002, month 6, P = 0.003) compared to Group I and higher titres (month 2, P = 0.001, month 6 P = 0.001) compared to Group I. At month 7, the geometric mean titres (GMTs) were comparable between groups and seroprotection reached 100% in both the groups. The incidence of any symptom per dose analysis reported during a 4-day follow-up period was significantly higher in Group I, 53% (52/98) of the documented doses compared to 37% (54/146) in Group II (P = 0.018). Conclusion: TwinrixTM vaccine is safe and highly immunogenic in Indian children. Further study of the high dose vaccine would determine if its two dose regimen is a feasible advantage. © 2002 Elsevier Science Ltd. All rights reserved. Keywords: Immunogenicity; TwinrixTM ; Hepatitis
1. Introduction Hepatitis A virus (HAV), is an important cause of childhood acquired acute hepatitis and liver failure in developing countries [1,2]. The spread of HAV is primarily by orofaecal route, but is rarely transmitted sexually or parenterally [3,4]. Epidemiological studies have also demonstrated that HAV exposure increases with low hygiene and increasing age [5]. The severity of hepatitis A is also known to be increased in unexposed young adults with high case fatality rates [6]. With the availability of safe inactivated HAV vaccine, the epidemiological pattern of HAV in children and high-risk populations can be greatly influenced [7]. ∗
Corresponding author. Tel.: +91-11-3232013; fax: +91-11-3239442. E-mail address: [email protected] (S.K. Sarin).
Hepatitis B virus (HBV), is also an important cause of hepatitis in children, in developing countries [8–10]. The risk of HBV infection becoming chronic has an inverse relation to age. The chronicity of HBV infection is around 90% if it is acquired below 1 year of age [11]. In countries like India with relatively high HBV prevalence, perinatal transmission of HBV is an important public health problem [8,12,13]. The most comprehensive approach to eliminate chronic HBV infection and related liver cancer has been the strategy of universal and high-risk group immunisation [14,15]. The two important causes of childhood acquired hepatitis, hepatitis A and B, can be prevented by vaccination. The incorporation of these two vaccines in the expanded program of immunisation (EPI) for children would have problems of compliance, even in the developed countries, due to the high cost and increased number of injections.
0264-410X/02/$ – see front matter © 2002 Elsevier Science Ltd. All rights reserved. PII: S 0 2 6 4 - 4 1 0 X ( 0 2 ) 0 0 0 4 6 - 4
R.C. Guptan et al. / Vaccine 20 (2002) 2102–2106
In view of this, a combined HAV and HBV vaccine has been developed recently [16]. A randomised open trial was initiated in healthy school children in India to evaluate the immunogenicity reactogenicity of a high combined hepatitis A and B vaccine compared to that of TwinrixTM .
2. Subjects and methods An open randomised study was initiated in September 1997 after prior approval of the Institutional Ethical Committee. Healthy school children were recruited in the study if they fulfilled the following inclusion criteria: age between 1 and 15 years, good physical condition as assessed by clinical-biochemical examination, informed consent from parents. The following exclusion criteria were followed: positive titres for anti-HAV, anti-HBs, anti-HBc, HBsAg, AST/ALT >1.5 times normal, history of significant hematologic, hepatic, renal, cardiac or respiratory disease. Hepatomegaly or features of chronic or acute hepatitis, chronic drug therapy, immunosuppressive or immunomodulatory therapy, history of allergic syndrome to vaccines, simultaneous participation in any other clinical trial, previous vaccination against hepatitis A or B. 2.1. Methodology of the trial This was undertaken according to good clinical practice (GCP) and quality of subject data recording and adverse experience monitoring was audited in-house and by independent regulatory compliance monitors. Adherence to the protocol requirements and verification of data generation accuracy was achieved through monitoring visits and methodologies detailed per standard operating procedures (SOPS). 2.2. Study design One hundred children fulfilled the inclusion criteria and were enrolled in the study. By computer generated random numbers they were allotted subject numbers to be included in one of the following treatment schedules. 2.2.1. Group I Group I received a combined high dose hepatitis A and B (HAB) vaccine containing per dose (0.5 ml volume) 720 ELISA units (EL.U) of inactivated HAV-HM 175 strain + 20 mcg recombinant hepatitis B surface antigen (HBsAg) administered according to a two-dose schedule (0, 6 months). 2.2.2. Group II Group II received TwinrixTM containing per 0.5 ml dose 360 EL.U inactivated HAV HM 175 strain + 10 mcg recombinant HBsAg administered according to a three-dose schedule (0, 1, 6 months).
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2.3. Criteria for evaluation Immunogenicity: Seroconversion rates for hepatitis A and seroprotection rates for hepatitis B at month 7. Seroconversion: This was defined as the appearance of antibodies (≥1 MIU/ml for anti-HBs antibodies and, ≥33 MIU/ml anti-HAV antibodies) in previously sero negative subjects. Seroprotection: This was defined for hepatitis B vaccine only and for anti-HBs levels ≥10 MIU/ml after the third dose of vaccine. Reactogenicity: This was defined as the nature and incidence of reaction after each dose of vaccine. After each vaccine dose local and general symptoms, including body temperature, were recorded by the subject or his/her parent or guardian on diary cards. A qualified nurse and co-investigator did site visits for three consecutive days post-vaccination, then every month, to monitor the subjects. Symptoms were graded as either absent, grade 1 (easily tolerated), grade 2 (sufficiently discomforting to interfere with normal daily activity) or grade 3 (prevented normal daily activity). The investigator assessed the relationship to vaccination of solicited and unsolicited symptoms at each subsequent visit of the vaccine. Any serious adverse event, including any case of hospitalization, was to be reported by the investigator to the sponsor within 24 hours of occurrence. 2.4. Statistical analysis Mean ages and gender were compared between groups using two way ANOVA; ratio of males to females between groups was compared using Fisher’s exact test. Anti-HAV and anti-HBs geometric mean titres (GMTs) were determined by taking the anti-log of the mean log titre transformations. GMTs were compared between groups at all time points (1, 2, 6, and 7 months) using Wilcoxon’s test. Anti-HAV seropositivity rates and anti-HBs seroprotection rates between groups, and incidence of symptoms between groups were also compared at all time points using Fisher’s exact test.
3. Results 3.1. Subjects Of the 100 children enrolled, 96 completed the vaccination trial. None of the four drop outs, two from each group, were due to adverse event. The demographic profiles of the two groups of children were comparable (Table 1). The mean age and gender was similar between the groups. The mean age of the total cohort was 7.9 ± 2.6 years (range 3–15 years). All the children were of Asian Indian origin.
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and the seroprotection rates reached 100% in both the groups.
Table 1 Demographic profile of study subjects Male
Female
Total
Range (years)
Group I (n) Mean age
29 8.2 ± 2.7
21 8.0 ± 2.7
50 8.2 ± 2.7
3–14
Group II (n) Mean age
27 7.7 ± 2.8
23 7.4 ± 2.2
50 7.6 ± 2.5
3–15
All (n) All mean
56 8 ± 2.4
44 7.7 ± 2.5
100 7.9 ± 2.6
3–15
3.2. Immunogenicity 3.2.1. Anti-HAV antibody response One month after the full vaccination course (at month 7) all subjects (100%) in both groups were seropositive for anti-HAV antibodies. Group I had significantly higher anti-HAV GMT at month 1 compared to Group II (P = 0.025, Wilcoxon’s test). While it reached comparable levels at month levels at month 7, the GMTs in mIU/ml Group I reached a peak of 6916 compared to 4865 mIU/ml in Group II. [None of the subjects in the study group developed jaundice or biochemical evidence of acute viral hepatitis during the course of seroconversion]. These results are presented in Table 2. 3.2.2. Anti-HBs antibody response One month after the full vaccination course, all subjects (100%) were seroprotected for anti-HBs antibodies (Table 3). It was interesting to note that in Group II a significantly higher number of subjects developed seroprotection at months 2 and 6 (P = 0.002, P = 0.003) compared to Group I, Fisher’s exact test. When quantitative titres were done, GMT of anti-HBs was also significantly higher in Group II at month 2 (P = 0.001) and month 6 (P = 0.001) compared to Group I. At month 7, the GMTs were comparable between the groups
3.3. Reactogenicity The overall incidence of any symptom per dose analysis reported during the 4-day follow-up period was significantly higher in Group I (Table 4): 53% (52 of 98) of the documented doses in Group I compared to 37% (54 of 146) in Group II (P = 0.018, Fisher’s exact test). 3.3.1. Local symptoms No grade 3 solicited local symptoms were reported, and all subjects with local symptoms recovered within 3–4 days. Soreness at injection site was the most frequently reported local symptom in both groups. Incidence of redness was seen in 10% (5/50) in Group I compared to 28% (14/50) in Group II (P = 0.04). 3.3.2. General symptoms No grade 3 general symptoms were reported. Low grade temperature (range 99–102 ◦ F) was the most prevalent general symptom in both groups; 28.6% (26/98) in Group I versus 19.9% (29/146) in Group II. 3.3.3. Unsolicited symptoms Unsolicited symptoms, i.e. those reported as ‘others’ or solicited complaints reported after the protocol specified follow-up period, were reported by 21 subjects (14 in Group I and 7 in Group II). Of these symptoms, three (12%) were local and 22 (88%) were general symptoms. Only five (20%) of these were found to be ‘possibly related’ to the vaccination (Table 5). 3.3.4. Serious adverse event One subject reputed a serious adverse event ‘possibly related” to the study vaccine. The event occurred in Group I and comprised low grade fever (100 ◦ F), redness at injection
Table 2 Post-vaccination seroconversion rates and GMTs of anti-HAV antibodies Group
Month
N
Seroconversion n (%)
95% CI LL
I
(97.9)a
GMT UL 424b
95% CI LL
UL
M1 M2 M6 M7
48 45 46 48
47 42 (93.3) 41 (89.1) 48 (100)
88.9 81.7 76.4 92.6
99.9 98.6 96.4 100
301 192 6916
279 187 120 4866
644 486 306 9830
M1 M2 M6 M7
47 48 48 48 –
37 46 41 42 –
64.3 85.7 72.2 92.6 –
89.3 99.5 93.9 100 –
295 514 245 4865 –
155 305 134 3229 –
560 867 449 7330 –
II
(78.7) (95.8) (85.4) (100)
M1, 2, 6, 7: month 1–7 post-vaccination; Group I, combined high dose HAV + HBV vaccine; N, number; Group II, TwinrixTM vaccine; GMT, geometric mean titre; 95% confidence interval. a Anti-HAV seroconversion rate statistically significantly higher in Group I at month 1 (P = 0.037), Fisher’s exact test. b Anti-HAV GMT statistically significantly higher in Group I, at month 1 (P = 0.02), Wilcoxon’s test.
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Table 3 Post-vaccination seroconversion, seroprotection and GMTs of anti-HBs antibodies Group
Month
N
Seroconversion n (%)
95% CI
Seroprotection n (%)
LL
UL
(72.4)a ,b
(63.8) (91.7) (97.4) (100)
95% CI
GMT
LL
UL
95% CI LL
UL
I
M1 M2 M6 M7
48 45 46 48
35 40 (88.9) 44 (95.7) 48 (100)
58.2 75.9 85.2 92.6
84.7 96.3 99.5 100
21 22 31 48
(43.8) (46.9) (67.4) (100)
29.5 33.7 52.0 92.6
58.8 64.2 80.5 100
13 12 20 3022
7 7 13 1760
22 19 31 5191
II
M1 M2 M6 M7
47 48 48 48
30 44 47 48
48.5 86.0 88.9 92.6
77.3 97.3 99.9 100
17 38 46 48
(36.2) (79.2)a (95.8)a (100)
22.7 65.0 85.7 92.6
51 89.5 99.9 100
14 88b 133b 5996b
6 46 72 3437
34 16 246 10458
Group I, combined high dose HAV + HBV vaccine; Group II, TwinrixTM vaccine; GMT, geometric mean titre; CI, confidence interval of 95%; M1, 2, 6, 7 month 1–7 post-vaccination. a Anti-HBs seroprotection rate statistically significantly higher in Group II at month 2, P = 0.002, month 6, P = 0.0003, (Fisher’s exact test). b Anti-HBs GMT statistically significantly higher in Group II at month 2, P = 0.001, month 6, P = 0.001 (Wilcoxon’s test).
Table 4 Incidence of local or general symptoms during post-vaccination period Group
N
All symptoms
Per dose analysis I II
98 146
52 (53.1%)a 54 (37.0%)
Per subject analysis I II
50 50
45 (90%) 41 (82%)
a Reactogenicity for all symptoms significantly higher in Group I compared to Group II (P = 0.018, Fisher’s exact test).
Table 5 Possibly related unsolicited symptoms WHO preferred term
Group I
Group II
Abdominal Pain Vomiting Pruritis
1 1 2 15 7 1 1 0 1 0 1
0 0 1 – 5 0 0 1 0 1
Coughing Pharyngitis Vomiting Pain abdomen Eye pain Earache Fever
site, abdominal pain and vomiting 2 days after the second dose of the vaccine. The child responded to the medication and recovered the following day.
4. Discussion The results of the present study clearly indicate the safety and satisfactory immure response of both vaccine regimens in children. One month after completion of the vaccination
course, almost 100% children became seropositive for HAV antibodies. This observation is similar to the immunogenicity for HAV vaccine reported after combined hepatitis A and B vaccine administration in young Europeans [17–20]. This result is also similar to the observation reported recently from China [21,22]. The seroconversion rate of 100% for HAV is also comparable to the seroconversion seen in relatively older Indian males taking HAV vaccine alone [23]. Both combined vaccines also achieved almost 100% seroprotection for HBV. This is similar to the observation with combined vaccine elsewhere [17–22]. Combination vaccines are not only known to minimise the number of doses required for universal vaccination, but they also increase compliance since less parental interventions are needed compared to what these individual vaccines would require. Moreover, studies have also demonstrated that HBV and HAV vaccines fare better when taken simultaneously or combined [24]. The complementary effect of the two viral antigens are not merely due to a local phenomenon due to activation of the cytokine pathways and macrophage activity [16], but also possibly due to stimulation of similar systemic pathways [25]. At completion of the study at month 7, rates of seroconversion and seroprotection were similar in both groups, the high dose as well as TwinrixTM . The GMTs of HAV were significantly higher in the first month after injection in the subjects who received the high dose (Group I). Subsequently, the GMTs became comparable at the end of the study. Similarly, the anti-HBs GMTs at month 2 were higher in Group II who received, however TwinrixTM , comparable with Group I at month 7. These results indicate that the immunogenicity of the high dose vaccination was comparable to TwinrixTM and that either schedule could be recommended. The results of the present study support the findings from recent European studies done in adult Grueb et al. [19], during which all subjects developed seroconversion for HAV and seroprotection for HBV at month 7. Adverse experiences
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were minimal in this adult population, even after high dose vaccine. In our study, one subject reported a serious adverse experience, possibly related to the vaccine. He reported to the investigators with pain abdomen, fever, vomiting 2 days after the second dose of the vaccine. However, he rapidly responded to medical treatment. It thus appears that increasing the dose of hepatitis A and B antigen increases the immunogenicity for HAV, but may enhance the reactogenicity in children. While earlier studies in India have reported that exposure to HAV below 5 years of age reached almost 90%, recent reports indicated that about 32% of children remained prone to develop acute hepatitis A, untill the age of 16 years [26]. This change in the epidemiology of HAV therefore cautions us to develop strategies to protect these adolescents and adults from hepatitis A. Since hepatitis B infection is most often acquired in India in the early childhood, it would be worthwhile to evaluate a strategy where a combined vaccine could decrease the incidence of both viral infections. Economic considerations would need to be carefully considered in a developing country like India. Furthermore, TwinrixTM vaccine not only demonstrates high immunogenicity but is also very safe and can be incorporated in the EPI programs. In conclusion, this combined vaccine regimens against hepatitis A and B were highly immunogenic in Indian children. They provide the advantage of fewer injections, lower cost, and possibility of easy incorporation within the present immunisation programs. References [1] Arora NK, Nanda SK, Gulati S, Ansari H, et al. Acute viral hepatitis types E, A and B singly or in combination in acute liver failure in children in north India. J Med Virol 1996;48(3):215–21. [2] Chadha MS, Chitambar SD, Naseem JS, Arankalle VA. Exposure of Indian children to hepatitis A virus and vaccination age. Ind J Med Res 1999;109:11–5. [3] Centers for Disease Control. Hepatitis A among drug abusers. MMWR 1998;37:297. [4] Centre for Disease control. Hepatatis A among homosexuals in United States, Canada and Australia. MMWR 1992;41:155–64. [5] Kiyohara T, Satoh T, Yamamoto H, Totsuka A, Moritsugn Y. The latest sero-epidemiological pattern of hepatitis A in Japan. J Med Sci Biol 1997;50:123–31. [6] Berge JJ, Drennan DA, Jacobs RJ, Jakins A, et al. The cost of hepatitis A infection in American adolescents and adults in 1997. Hepatology 2000;31:469–73. [7] Bader TF. Hepatitis A vaccine. Am J Gastroenterol 1995;91:217–22. [8] Nayak NC, Panda SK, Zuckerman AJ, et al. Dynamics and impact of perinatal transmission of hepatitis B virus in North India. J Med Viral 1987;21:137–45. [9] Chen HL, Chang MH, Ni YH, Hsu HY, Lee CY, Chen DS, et al. Seroepidemiology of hepatitis B virus infection and children. JAMA 1996;276:906–8.
[10] Fuji Sawa T, Komatsu H, Inui A, Sogo T, et al. Long-term outcome of chronic hepatitis B in adolescents or young adults in follow up from childhood. J Pedrat Gastroenterol Nutr 2000;30:201– 6. [11] McMohan BJ, Alward WLM, Hart DO, et al. Acute hepatitis B virus infection relation of age to clinical expression of disease and subsequent development of the carrier state. J Infet Dis 1985;151:563–99. [12] Xu ZY, Liu CB, Francis DP, et al. Prevention of perinatal acquisition of hepatitis B virus carriage using vaccine: preliminary report of a randomised double blind placebo controlled and comparative trial. Paediatrics 1985;7:713–5. [13] Guptan RC, Thakur V, Sarin SK. Hepatitis B in high risk groups in India. In: Sarin SK, Singal AK, editors. Hepatitis B in India: problems and prevention. Ist ed. Delhi: CBS Publishers, 1996. p. 39– 50. [14] Centers for Disease Control. Hepatitis B virus, a comprehensive strategy for eliminating transmission in the United States through universal childhood vaccination. Recommendation of the Immunisation Practices Advisory Committee (ACIP). MMWR 1991;40:13–7. [15] Poovorawan Y, Sanpavat S, Pong Punlert W, et al. Long-term efficacy of hepatitis B vaccine in infants born to HBeAg positive mother: effect of vaccination with a yeast derived vaccine according to different schedules with and without concomitant hepatitis B immunoglobulin. Pediatr Inf Dis J 1992;11:816–8. [16] Van Damme P, Thoelen S, Cramm M, Safary A, Mehens A. Reactogenicity and immunogenicity of a combined hepatitis A and B vaccine in healthy adults. Viral Hep Liver Dis 1994;514–6. [17] Bruguera M, Bayas JM, Vilella A, Tural C, Gonzale A, et al. Immunogenicity and reactogenicity of a combined hepatitis A and B vaccine in young adults. Vaccine 1996;14:1407–11. [18] Knoll A, Holtentrager B, Kain ZJ, Bretschneider B, Jilg W. Immunogenicity of a combined hepatitis A and B vaccine in healthy young adults. Vaccine 2000;18:2029–32. [19] Greub G, Genton B, Safary A, Thoelen S, Frei PC. Comparison of the reactogenicity and immunogenicity of a two injection combined high dose hepatitis A and hepatitis B vaccine to those of TwinrixTM . Vaccine 2001;19:1113–7. [20] Herck KV, Damme PV, Callard F, Thoelen S. Two dose combined vaccination against hepatitis A and B in healthy subjects aged 11–18 years. Scand J Gastroenterol 1999;12:1236–40. [21] Tsai IJ, Chang MH, Chen HL, Ni YH, Lee PT, Chin TY, et al. Immunogenicity and reactogenicity of the combined hepatitis A and B vaccine in young adults. Vaccine 2001;19:437–41. [22] Lee SD, Chan CY, Yu MI, Wang YJ, Chang FY, Lo KJ, et al. A two dose combined hepatitis A and B vaccine in Chinese youngster. J Med Virol 1999;59:1–4. [23] Das K, Jain A, Gupta RK, Kar P. Immunogenicity and reactogenicity of an inactivated hepatitis A vaccine in Indian adults. Nat Med J Ind 1999;12:268–9. [24] Czeschinski PA, Binding N, Witting U. Hepatitis A and hepatitis B vaccinations: immunogenicity of combined vaccine and of simultaneously or separately applied single vaccines. Vaccine 2000;18:1074–80. [25] Ambrosh F, Niedermann G, Andre FE, Delem A, Gregor H, Hafmann H, et al. Clinical and immunological investigation of a new combined hepatitis A and hepatitis B vaccine. J Med Virol 1994;44:452–6. [26] Thakur V, Guptan RC, Bagga S, Safary A, Sarin SK. Prevalence of hepatitis A antibodies in children in India. Ind J Gastroenterol 1998;17:27.