- Email: [email protected]
P.350 Randomised controlled trial: 2- vs 3-dose hepatitis B immunization of adolescents
$168
Journal of Clinical Virology 2006, Vol 36 (suppl 2)
Results: HBV specific T cells were detectable in the Hepimmune group after the second and in the standard HBV vaccine group after the third vaccination. IFN-~/ production of T cells was significantly higher (p<0.001) after the third vaccination (median spots increment: 59 vs. 17 in the Hepimmune vs. standard group). Proliferative responses were also significantly (p < 0.01 ) higher in the Hepimmune group after the second to fourth vaccination (median stimulation indices: 4.1 vs. 0.9, 18.6 vs. 2.2, 9.8 vs. 2.2, resp.). Anti-HBs antibody titers could already be detected after the first immunization in 9/15 of Hepimmune vaccinated probands while it was only observed in 1/15 probands of the later group. Titers differed significantly (p<0.05) following all four vaccinations (median titer [IU/L]: 37 vs. 0, 114 vs. 0, 201 vs. 30, and 705 vs. 261, resp.). Conclusion: Hepimmune appears as a good candidate to induce strong cellular and early humoral immune responses in a short time immunization protocol. ~
Comparative evaluation of three different commercial assays for quantitation of anti-HBs levels after immunization with recombinant vaccines
J.C. Miguel 1, M.L.A. Oliveira 1, L.A.B. Camacho 2, C.F.T. Yoshida 1, K.M.R. Do 61 *, R.M. Martins 3. 1National Reference Laboratory
for Viral Hepatitis, 2National Public Health School, Oswaldo Cruz Foundation, Rio de Janeiro; 3National Immunization Program, Ministry of Health, Brasilia, Brazil Background and Objectives: Worldwide, Hepatitis B Virus (HBV) infection is one of the major risk factors for liver disease. Recombinant vaccines use to induce seroprotection in more than 95% of young and healthy immunized subjects, preventing further clinically significant hepatitis. Although anti-HBs testing is not routinely recommended after immunization, the determination of antibody titers is essential to release new HBV vaccines, as to assess alternative vaccination schedules. In this study, three different test systems widely used for determination of anti-HBs levels were compared. Methods: Anti-HBs quantitation was performed in 163 samples, collected 1-2 months after administration of the third dose of Butang ® or Engerix-B ® vaccines. Samples were tested using a chemoluminescent assay (test A, ACCESS AbHBs II, BeckmanCoulter), a microparticle enzyme immunoassay (test B, IMx AUSAB, Abbott Laboratories) and a manual EIA (test C, ETI-AB-AUK-3, Diasorin). Geometric Mean Titers (GMT) were logarithmically transformed and the correlation between the assays was analyzed by linear regression. The 95% confidence intervals were constructed for the estimates. Results: Seroconversion frequencies were 90.2% (95%C1: 84.5-94.3), 91.4% (86.0-95.2) and 89.6% (83.8-93.8) detected by tests A, B and C, respectively. The three assays showed concordant results. For Access/Imx, linear coefficients (R) were 0.960 (P<0.001); for Access/Diasorin, R=0.913 (P<0.001) and for IMx/Diasorin, R = 0.943 (P < 0.001 ). When the different vaccines were considered, similar results were observed. Conclusion: All three commercial assays showed comparable results and were suitable for immunogenicity studies. Due to the lower cost and operational facilities, the manual EIA could be a helpful alternative in countries with limited resources and for small laboratories. ~
Efficacy of hepatitis B vaccination on hepatitis B prevention and on hepatocellular carcinoma in Long An county, Guangxi Province, China
R. Li 1 *, Yang 1, J. Gong 1, Y. Li 1, Y. Nong 1, K. Fang 2, Z. Xu 3, C. Liu4, H. Zhuang 5. 1Dept. Virology, Guangxi Center for Disease
Prevention and Control, Nanning; 2Dept. EPI, Longan Center for Disease Prevention and Control, Long An; 3Dept. Epidemiology, Shanghai Fudan University, Shanghai; 4DepL Hepatitis, Chinese Center for Disease Control and Prevention, 5DepL Medicine, Beijing University, Beijing, China Background: Hepatitis B and primary liver cancer (PLC) are major common diseases and important public health problem in Long An county, Guangxi province, South China.
Abstracts, 12th ISHVLD
Objectives: To evaluate the efficacy of preventive HBV infection and to monitor the incidence of chronic liver damage and PLC in children to see possible impact of the program of Long An that was launched in 1985. Methods: (1) a stratified random sampling of 1000 children in 1987 birth cohorts was recruited for long term follow-up at the age 1-18 years. (2) Cross-seroepidemiological survey was carried out in 1985 before the program and 20 years later (2005). (3) To evaluate the possible impact on incidence of chronic liver disease and PLC, we have monitored the annual incidence of PLC in children since 1985. HBsAg, anti-HBs and anti-HBc were tested by RIA. Results: At 18 years after vaccination, the annual seropositivity for HBsAg maintained at a low levels of 1.7% (1.4-2.8%), the annual effectiveness ranged from 84.1% (at 1-2 years) to 92.5% (at 18 years). Seroepidemiologic survey was done in 5000 subjects aged 1-60 years. The HBsAg positive rate markedly reduced in 1-29 age group, paticularly in 1-15 age group, which reduced 100% - 83%. To evaluate the possible impact on incidence of chronic liver disease and PLC, we have monitored the annual incidence of hepatitis B and PLC in children since 1987. The incidence of hepatitis B was 3.60 per 100,000 in children aged 1-19 years, it decreased by 89.36% as compared with the incidence of 33.85 per 100,000 in same age group in 1987, and the incidence of PLC declined from 0.61-5.74 per 100,000 children aged 1-19 years old in 1969-1988 to 0-3.31 per 100,000 in 1989-1992 and 0 per 100,000 in 1993-2005. Conclusion: Mass HB vaccination program in Long An county has proved to be effective in the control of HBV infection. The incidence of liver damage and PLC in the childhood and the adolescent (10-29) have been decreased notably after mass Hepatitis B vaccination program.
•
Randomised controlled trial: 2- vs 3-dose hepatitis B immunization of adolescents
L. Heron 1 *, O. Selnikova2, A. Moiseieva2, R Van Damme 3, M. Van der Wielen 3, K. Levie4, B. Hoet 5, M. Stoffel 5. 1Public Health Unit,
Sydney South West Area Health Service, Liverpool, NSW, Australia, 2State Enterprise Center of Immunobiological Preparations, Spusk Protasiv Yar, 4, 03038 Kiev, Ukraine, 3 WHO Collaborating Centre for the Prevention and Control of Viral Hepatitis, University of Antwerp - Campus "Drie Eiken", Universiteitsplein 1, 2610 Wilrijk; 4Ecole de Sant6 Publique, Clos Chapelle-aux-Champs, 1200 Brussels; 5GlaxoSmithKline, Biological& Rixensart, Belgium Background and Objectives: Compared to a 3-dose regimen, a 2-dose regimen for hepatitis B (HB) immunization of adolescents may improve completion rates and is more feasible and economically attractive to implement. Objective: compare reactogenicity, safety and immunogenicity of 2-dose and 3-dose HB immunization regimens in adolescents. Methods: Study design: Company-sponsored, subject- and assessor-blind (only persons giving injections were not blind), randomised (Group A vs Group B, 2:1) trial in 4 centres. Subjects: Healthy 11-15 year olds; not pregnant; no history of HB vaccination, intravenous drug use, receipt of blood products within 3 months, or HB exposure within 6 weeks; HBsAg, anti-HBc & anti-HBs negative pre-vaccination. Injections (IM deltoid): Group A: thiomersal-free Engerix-B TM (20pg, 1 mL) at Months 0, 6; placebo Month 1. Group B: preservative-free Engerix-B TM (10 pg, 0.5 mL) at Months 0, 1, 6. Blood samples at pre-vaccination, Months 1,2,6,7. Reactogenicity/safety: 4-day symptom diary and 30-day selfreported symptoms after each injection; serious adverse event follow-up 6 months after last injection. Results: Enrollment: Group A (GpA): 258; Group B (GpB): 126. According to protocol (ATP) reactogenicity cohort: The 253 GpA subjects received 756 injections; completed 755 diaries. The 121 GpB subjects received 360 injections; completed 358 diaries. Although 20pg injections produced more local symptoms, except for injection site pain (less frequent with placebo), the frequencies of symptoms after each injection type (10pg, 20pg or placebo) were not significantly different, p>0.05. By completion, GpA and GpB subjects cumulatively reported each symptom (symptoms after placebo excluded) in closely similar frequencies.
Posters: 05. Vaccines
ATP immunogenicity cohort characteristics: GpA (n = 241) mean age 12.9±1.2y, 49% male, 97% white; GpB (n=113) mean age 12.7±1.4y, 49% male, 97% white. Seroprotection (anti-HBs >lOmlU/mL, Month 7): GpA 96.7% (GMT 2738, 95% CI: 2071-3620 mlU/mL); GpB 98.2% (GMT 7239, 95%C1: 5247-9985mlU/mL); difference in seroprotection -1.5%; exact 90% CI: -6.4% to 3.9%. Conclusion: Both regimens were safe with similar reactogenicity profiles and seroprotection rates.
[•1]
Impact of routine childhood hepatitis B immunization programs in eliminating hepatitis B virus transmission in the Pacific
S.R. Bialek 1 ~, G.L. Armstrong 1, W.A. Bower 1, RR. Patel 1, J.R Chaine 2, L. Helgenberger3, S.T. Goldstein 1, I.T. Williams 1.
1Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, USA, 2Regional Epidemiology, Pacific Islands Health Officers Association, 3National Immunization Program, Department of Health, Education and Social Affairs, Pohnpei, Federated States of Micronesia Background and Objectives: Historically, hepatitis B virus (HBV) infection was endemic in the Pacific Islands. Prior to introduction of routine infant hepatitis B (HB) immunization, up to 70% of children had been infected with HBV by 10 years of age and 15% were chronically infected. We conducted seroprevalence surveys at least 10 years after introduction of routine infant HB immunization in 3 Pacific Island jurisdictions to evaluate its impact on the prevalence of HBV infection among children in this region. Methods: We collected serum specimens from children aged 7-8 years in Samoa in 1995, 2-6 years in Chuuk, Federated States of Micronesia (FSM) in 2000, 10-11 years in Palau in 2003, and 2-9 years in Pohnpei, FSM in 2005. Children enrolled in Palau were required to have received HB vaccine within 1 week of birth and completed 3 doses by 12 months of age. Specimens were tested for HB surface antigen (HBsAg) and antibodies to HB core antigen (total anti-HBc) and HBsAg (anti-HBs). HB vaccination coverage was determined from health department vaccination registries. We defined chronic HBV infection as the presence of HBsAg and resolved infection as the presence of anti-HBc and anti-HBs. Vaccine effectiveness was defined as the proportion of children who received 3 doses of HB vaccine and did not have chronic infection. Results: We enrolled 432 children from Samoa, 365 from Chuuk, 192 from Palau and 479 from Pohnpei. Three dose and three dose including birthdose HB vaccination coverage was 91% and 75% respectively in Samoa, 87% and 50% in Chuuk, 100% and 85% in Palau, and 90% and 85% in Pohnpei. Chronic HBV infection prevalence ranged from 0% to 2.5%: 0.5% (2/432) in Samoa, 2.5% (9/365) in Chuuk, 0% in Palau, and 1.5% (7/479) in Pohnpei. Evidence of resolved infection was found in 11 participants (2.5%) in Samoa, 51 (14%) in Chuuk, 11 (6%) in Palau, and 11 (2%) in Pohnpei. Of chronically infected participants, none in Samoa or Chuuk, but 6 in Pohnpei, had received a birth dose of HB vaccine. Vaccine effectiveness was 100% in Samoa, 98% in Chuuk, 100% in Palau, and 99% in Pohnpei. Conclusion: Routine hepatitis B vaccination has resulted in the near-elimination of chronic infection in vaccinated cohorts of children in the Pacific Islands. HB vaccine coverage and effectiveness is high in this region, despite the geographical challenge in providing HB vaccine at birth and completing vaccination according to the recommended schedule.
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Efficacy of hepatitis B vaccine in preventing clinical hepatitis B in children: a 13 years follow-up
J. Gong 1 ', RIC. Li 1, JIY. Yang 1, X.R. Chen 2, C.B. Liu 3, K. Zhao 4.
1Virology Division, Guangxi Provincial CDC, 2Virology Division, Long-An County CDC, Nanning; 3Virology Institute, China CDC, 4 Virology Division, Beijing Institute of Biological Products, Beijing, China Background and Objectives: To demonstrate the effect of the first dosing schedule of hepatitis B (HB) vaccine on the efficacy
$169
in protecting children against HB and the effect of vaccination on the prognosis of HB patients. Methods: Since 1987, Long'an County in China, a HB hyperendemic area, started a prevention program to combat this disease by implementing no screening of pregnant women for HBsAg and universal immunization of newborns within 72 hours of birth. Infants born between 1987-1999 were followed up for the prevalence and prognosis of hepatitis B. Results: Birth cohort during the 13 years was 63,332. The annual vaccination coverage averaged at 89%, and 63.8% of subjects received first dose of HB vaccine within 72h of birth. A total of 7 clinical HB cases were reported, giving the accumulative incidence rate of 11.1/100,000. The annual incidence rate was 0.85/100,000, a drop of 97% compared to that before vaccination (33/100,000 children aged 0-9 years). The accumulative incidence of acute HB in children who received the initial dose within 72h of birth was 5.6/100,000, as compared to 14.7/100,000 in those not immunized within 72h of birth. Among the children of HBsAg-negative mothers, the incidence was 4.0/100,000 in the vaccinated group vs.16.4/100,000 in the unvaccinated group. Among the infants born to HBsAg-positive mothers, the incidence was 29. 8/100,000 in the vaccinated vs.121.4/100,000 in the unvaccinated. The overall protective efficacy was 69.2% in preventing acute hepatitis B. In the children immunized with the first dose within 72 h of birth, the efficacy was 80.6%, but it dropped to 49.1% in the children not immunized within 72h. Compared with the vaccinated children of HBsAg(-) mothers, the relative risk (RR) of acquiring acute HB was 4.1 for the unvaccinated children of HBsAg(-) mothers, 7.45 for the vaccinees of HBsAg(+) mothers, and 30.35 for the unvaccinees of HBsAg(+) mothers. The follow-up study of HB patients for 2-5 years suggested that the clinical cure rate was 4/5 in the vaccinated cases, 1/2 in the unvaccinated, 3/3 in the cases with HBsAg(-) mothers and 1/3 in those born to HBsAg(+) mothers. Among the children of HBsAg(+) mothers, the vaccinees had better prognosis than the unvaccinees. Among the immunized children of HBsAg(+) mothers, the prognosis was better in older children compared with the younger. Conclusion: The implementation of universal infant immunization for 13 years has helped to significantly improve the disease outcomes. HBV carriage in mothers and the timeliness of first dosing are important factors in the protective efficacy of HBV vaccine.
[-P-~
Efficiency of HBV vaccination for healthcare workers
A. Tanomand 2, S.H. Montazam 1 *, A. Khaki 2, A. Sani 2, M. Najari nabi 2, M. Kafshnochi 1. 1Microbiology, Bonab Islamic Azad
University, Bonab; 2Microbiology, Tabriz Medical Sciences University, Tabriz, Iran Background and Objectives: Hepatitis B is a serious disease caused by a virus that attacks the liver. HBV can cause chronic infection, cirrhosis and/or cancer of the liver. HBV vaccine prevents infection and related diseases to HBV. The aim of this study is estimating efficacy of HBV vaccine in medical group individuals. Methods: In a cross sectional study in 2004, blood samples of 240 persons, who were vaccinated compactly (1 to 6 month before), were collected. Then HBsAb were estimated by EIA method. The antibody more than 10 IU/ml seems to be protective. Negative cases were vaccinated for fourth time and have studied for HBV serologic markers. Data were analyzed by SPSS version 12. Results: The presence of HBsAb over 101U were seen in 210 persons. Therefore the efficacy of vaccine was 87.5%. The lower limit was 0, and upper limit was 542 IU. After fourth dose of vaccine, 20 persons had HBsAb over 101U, but 10 persons had negative results in the second test and 6 persons had HBsAg and Anti-HBcAb positive. Conclusion: The findings showed that vaccine efficacy was similar as in other studies (85-99%). In view of the 12.5% nonimmune subjects, it is better that storage conditions and efficiency of available vaccine will be studied. With respect to the HBsAg and Anti-HBcAb results, those subjects had past infection especially in the vaccination time. Vaccination is seriously recommended, because use of vaccine against HBV is useful, especially in endemic areas, and prevents complications of infection in the future. Also, it is recommended to measure HBV serologic markers before marriage.
Journal of Clinical Virology 2006, Vol 36 (suppl 2)
Results: HBV specific T cells were detectable in the Hepimmune group after the second and in the standard HBV vaccine group after the third vaccination. IFN-~/ production of T cells was significantly higher (p<0.001) after the third vaccination (median spots increment: 59 vs. 17 in the Hepimmune vs. standard group). Proliferative responses were also significantly (p < 0.01 ) higher in the Hepimmune group after the second to fourth vaccination (median stimulation indices: 4.1 vs. 0.9, 18.6 vs. 2.2, 9.8 vs. 2.2, resp.). Anti-HBs antibody titers could already be detected after the first immunization in 9/15 of Hepimmune vaccinated probands while it was only observed in 1/15 probands of the later group. Titers differed significantly (p<0.05) following all four vaccinations (median titer [IU/L]: 37 vs. 0, 114 vs. 0, 201 vs. 30, and 705 vs. 261, resp.). Conclusion: Hepimmune appears as a good candidate to induce strong cellular and early humoral immune responses in a short time immunization protocol. ~
Comparative evaluation of three different commercial assays for quantitation of anti-HBs levels after immunization with recombinant vaccines
J.C. Miguel 1, M.L.A. Oliveira 1, L.A.B. Camacho 2, C.F.T. Yoshida 1, K.M.R. Do 61 *, R.M. Martins 3. 1National Reference Laboratory
for Viral Hepatitis, 2National Public Health School, Oswaldo Cruz Foundation, Rio de Janeiro; 3National Immunization Program, Ministry of Health, Brasilia, Brazil Background and Objectives: Worldwide, Hepatitis B Virus (HBV) infection is one of the major risk factors for liver disease. Recombinant vaccines use to induce seroprotection in more than 95% of young and healthy immunized subjects, preventing further clinically significant hepatitis. Although anti-HBs testing is not routinely recommended after immunization, the determination of antibody titers is essential to release new HBV vaccines, as to assess alternative vaccination schedules. In this study, three different test systems widely used for determination of anti-HBs levels were compared. Methods: Anti-HBs quantitation was performed in 163 samples, collected 1-2 months after administration of the third dose of Butang ® or Engerix-B ® vaccines. Samples were tested using a chemoluminescent assay (test A, ACCESS AbHBs II, BeckmanCoulter), a microparticle enzyme immunoassay (test B, IMx AUSAB, Abbott Laboratories) and a manual EIA (test C, ETI-AB-AUK-3, Diasorin). Geometric Mean Titers (GMT) were logarithmically transformed and the correlation between the assays was analyzed by linear regression. The 95% confidence intervals were constructed for the estimates. Results: Seroconversion frequencies were 90.2% (95%C1: 84.5-94.3), 91.4% (86.0-95.2) and 89.6% (83.8-93.8) detected by tests A, B and C, respectively. The three assays showed concordant results. For Access/Imx, linear coefficients (R) were 0.960 (P<0.001); for Access/Diasorin, R=0.913 (P<0.001) and for IMx/Diasorin, R = 0.943 (P < 0.001 ). When the different vaccines were considered, similar results were observed. Conclusion: All three commercial assays showed comparable results and were suitable for immunogenicity studies. Due to the lower cost and operational facilities, the manual EIA could be a helpful alternative in countries with limited resources and for small laboratories. ~
Efficacy of hepatitis B vaccination on hepatitis B prevention and on hepatocellular carcinoma in Long An county, Guangxi Province, China
R. Li 1 *, Yang 1, J. Gong 1, Y. Li 1, Y. Nong 1, K. Fang 2, Z. Xu 3, C. Liu4, H. Zhuang 5. 1Dept. Virology, Guangxi Center for Disease
Prevention and Control, Nanning; 2Dept. EPI, Longan Center for Disease Prevention and Control, Long An; 3Dept. Epidemiology, Shanghai Fudan University, Shanghai; 4DepL Hepatitis, Chinese Center for Disease Control and Prevention, 5DepL Medicine, Beijing University, Beijing, China Background: Hepatitis B and primary liver cancer (PLC) are major common diseases and important public health problem in Long An county, Guangxi province, South China.
Abstracts, 12th ISHVLD
Objectives: To evaluate the efficacy of preventive HBV infection and to monitor the incidence of chronic liver damage and PLC in children to see possible impact of the program of Long An that was launched in 1985. Methods: (1) a stratified random sampling of 1000 children in 1987 birth cohorts was recruited for long term follow-up at the age 1-18 years. (2) Cross-seroepidemiological survey was carried out in 1985 before the program and 20 years later (2005). (3) To evaluate the possible impact on incidence of chronic liver disease and PLC, we have monitored the annual incidence of PLC in children since 1985. HBsAg, anti-HBs and anti-HBc were tested by RIA. Results: At 18 years after vaccination, the annual seropositivity for HBsAg maintained at a low levels of 1.7% (1.4-2.8%), the annual effectiveness ranged from 84.1% (at 1-2 years) to 92.5% (at 18 years). Seroepidemiologic survey was done in 5000 subjects aged 1-60 years. The HBsAg positive rate markedly reduced in 1-29 age group, paticularly in 1-15 age group, which reduced 100% - 83%. To evaluate the possible impact on incidence of chronic liver disease and PLC, we have monitored the annual incidence of hepatitis B and PLC in children since 1987. The incidence of hepatitis B was 3.60 per 100,000 in children aged 1-19 years, it decreased by 89.36% as compared with the incidence of 33.85 per 100,000 in same age group in 1987, and the incidence of PLC declined from 0.61-5.74 per 100,000 children aged 1-19 years old in 1969-1988 to 0-3.31 per 100,000 in 1989-1992 and 0 per 100,000 in 1993-2005. Conclusion: Mass HB vaccination program in Long An county has proved to be effective in the control of HBV infection. The incidence of liver damage and PLC in the childhood and the adolescent (10-29) have been decreased notably after mass Hepatitis B vaccination program.
•
Randomised controlled trial: 2- vs 3-dose hepatitis B immunization of adolescents
L. Heron 1 *, O. Selnikova2, A. Moiseieva2, R Van Damme 3, M. Van der Wielen 3, K. Levie4, B. Hoet 5, M. Stoffel 5. 1Public Health Unit,
Sydney South West Area Health Service, Liverpool, NSW, Australia, 2State Enterprise Center of Immunobiological Preparations, Spusk Protasiv Yar, 4, 03038 Kiev, Ukraine, 3 WHO Collaborating Centre for the Prevention and Control of Viral Hepatitis, University of Antwerp - Campus "Drie Eiken", Universiteitsplein 1, 2610 Wilrijk; 4Ecole de Sant6 Publique, Clos Chapelle-aux-Champs, 1200 Brussels; 5GlaxoSmithKline, Biological& Rixensart, Belgium Background and Objectives: Compared to a 3-dose regimen, a 2-dose regimen for hepatitis B (HB) immunization of adolescents may improve completion rates and is more feasible and economically attractive to implement. Objective: compare reactogenicity, safety and immunogenicity of 2-dose and 3-dose HB immunization regimens in adolescents. Methods: Study design: Company-sponsored, subject- and assessor-blind (only persons giving injections were not blind), randomised (Group A vs Group B, 2:1) trial in 4 centres. Subjects: Healthy 11-15 year olds; not pregnant; no history of HB vaccination, intravenous drug use, receipt of blood products within 3 months, or HB exposure within 6 weeks; HBsAg, anti-HBc & anti-HBs negative pre-vaccination. Injections (IM deltoid): Group A: thiomersal-free Engerix-B TM (20pg, 1 mL) at Months 0, 6; placebo Month 1. Group B: preservative-free Engerix-B TM (10 pg, 0.5 mL) at Months 0, 1, 6. Blood samples at pre-vaccination, Months 1,2,6,7. Reactogenicity/safety: 4-day symptom diary and 30-day selfreported symptoms after each injection; serious adverse event follow-up 6 months after last injection. Results: Enrollment: Group A (GpA): 258; Group B (GpB): 126. According to protocol (ATP) reactogenicity cohort: The 253 GpA subjects received 756 injections; completed 755 diaries. The 121 GpB subjects received 360 injections; completed 358 diaries. Although 20pg injections produced more local symptoms, except for injection site pain (less frequent with placebo), the frequencies of symptoms after each injection type (10pg, 20pg or placebo) were not significantly different, p>0.05. By completion, GpA and GpB subjects cumulatively reported each symptom (symptoms after placebo excluded) in closely similar frequencies.
Posters: 05. Vaccines
ATP immunogenicity cohort characteristics: GpA (n = 241) mean age 12.9±1.2y, 49% male, 97% white; GpB (n=113) mean age 12.7±1.4y, 49% male, 97% white. Seroprotection (anti-HBs >lOmlU/mL, Month 7): GpA 96.7% (GMT 2738, 95% CI: 2071-3620 mlU/mL); GpB 98.2% (GMT 7239, 95%C1: 5247-9985mlU/mL); difference in seroprotection -1.5%; exact 90% CI: -6.4% to 3.9%. Conclusion: Both regimens were safe with similar reactogenicity profiles and seroprotection rates.
[•1]
Impact of routine childhood hepatitis B immunization programs in eliminating hepatitis B virus transmission in the Pacific
S.R. Bialek 1 ~, G.L. Armstrong 1, W.A. Bower 1, RR. Patel 1, J.R Chaine 2, L. Helgenberger3, S.T. Goldstein 1, I.T. Williams 1.
1Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, USA, 2Regional Epidemiology, Pacific Islands Health Officers Association, 3National Immunization Program, Department of Health, Education and Social Affairs, Pohnpei, Federated States of Micronesia Background and Objectives: Historically, hepatitis B virus (HBV) infection was endemic in the Pacific Islands. Prior to introduction of routine infant hepatitis B (HB) immunization, up to 70% of children had been infected with HBV by 10 years of age and 15% were chronically infected. We conducted seroprevalence surveys at least 10 years after introduction of routine infant HB immunization in 3 Pacific Island jurisdictions to evaluate its impact on the prevalence of HBV infection among children in this region. Methods: We collected serum specimens from children aged 7-8 years in Samoa in 1995, 2-6 years in Chuuk, Federated States of Micronesia (FSM) in 2000, 10-11 years in Palau in 2003, and 2-9 years in Pohnpei, FSM in 2005. Children enrolled in Palau were required to have received HB vaccine within 1 week of birth and completed 3 doses by 12 months of age. Specimens were tested for HB surface antigen (HBsAg) and antibodies to HB core antigen (total anti-HBc) and HBsAg (anti-HBs). HB vaccination coverage was determined from health department vaccination registries. We defined chronic HBV infection as the presence of HBsAg and resolved infection as the presence of anti-HBc and anti-HBs. Vaccine effectiveness was defined as the proportion of children who received 3 doses of HB vaccine and did not have chronic infection. Results: We enrolled 432 children from Samoa, 365 from Chuuk, 192 from Palau and 479 from Pohnpei. Three dose and three dose including birthdose HB vaccination coverage was 91% and 75% respectively in Samoa, 87% and 50% in Chuuk, 100% and 85% in Palau, and 90% and 85% in Pohnpei. Chronic HBV infection prevalence ranged from 0% to 2.5%: 0.5% (2/432) in Samoa, 2.5% (9/365) in Chuuk, 0% in Palau, and 1.5% (7/479) in Pohnpei. Evidence of resolved infection was found in 11 participants (2.5%) in Samoa, 51 (14%) in Chuuk, 11 (6%) in Palau, and 11 (2%) in Pohnpei. Of chronically infected participants, none in Samoa or Chuuk, but 6 in Pohnpei, had received a birth dose of HB vaccine. Vaccine effectiveness was 100% in Samoa, 98% in Chuuk, 100% in Palau, and 99% in Pohnpei. Conclusion: Routine hepatitis B vaccination has resulted in the near-elimination of chronic infection in vaccinated cohorts of children in the Pacific Islands. HB vaccine coverage and effectiveness is high in this region, despite the geographical challenge in providing HB vaccine at birth and completing vaccination according to the recommended schedule.
rP...•
Efficacy of hepatitis B vaccine in preventing clinical hepatitis B in children: a 13 years follow-up
J. Gong 1 ', RIC. Li 1, JIY. Yang 1, X.R. Chen 2, C.B. Liu 3, K. Zhao 4.
1Virology Division, Guangxi Provincial CDC, 2Virology Division, Long-An County CDC, Nanning; 3Virology Institute, China CDC, 4 Virology Division, Beijing Institute of Biological Products, Beijing, China Background and Objectives: To demonstrate the effect of the first dosing schedule of hepatitis B (HB) vaccine on the efficacy
$169
in protecting children against HB and the effect of vaccination on the prognosis of HB patients. Methods: Since 1987, Long'an County in China, a HB hyperendemic area, started a prevention program to combat this disease by implementing no screening of pregnant women for HBsAg and universal immunization of newborns within 72 hours of birth. Infants born between 1987-1999 were followed up for the prevalence and prognosis of hepatitis B. Results: Birth cohort during the 13 years was 63,332. The annual vaccination coverage averaged at 89%, and 63.8% of subjects received first dose of HB vaccine within 72h of birth. A total of 7 clinical HB cases were reported, giving the accumulative incidence rate of 11.1/100,000. The annual incidence rate was 0.85/100,000, a drop of 97% compared to that before vaccination (33/100,000 children aged 0-9 years). The accumulative incidence of acute HB in children who received the initial dose within 72h of birth was 5.6/100,000, as compared to 14.7/100,000 in those not immunized within 72h of birth. Among the children of HBsAg-negative mothers, the incidence was 4.0/100,000 in the vaccinated group vs.16.4/100,000 in the unvaccinated group. Among the infants born to HBsAg-positive mothers, the incidence was 29. 8/100,000 in the vaccinated vs.121.4/100,000 in the unvaccinated. The overall protective efficacy was 69.2% in preventing acute hepatitis B. In the children immunized with the first dose within 72 h of birth, the efficacy was 80.6%, but it dropped to 49.1% in the children not immunized within 72h. Compared with the vaccinated children of HBsAg(-) mothers, the relative risk (RR) of acquiring acute HB was 4.1 for the unvaccinated children of HBsAg(-) mothers, 7.45 for the vaccinees of HBsAg(+) mothers, and 30.35 for the unvaccinees of HBsAg(+) mothers. The follow-up study of HB patients for 2-5 years suggested that the clinical cure rate was 4/5 in the vaccinated cases, 1/2 in the unvaccinated, 3/3 in the cases with HBsAg(-) mothers and 1/3 in those born to HBsAg(+) mothers. Among the children of HBsAg(+) mothers, the vaccinees had better prognosis than the unvaccinees. Among the immunized children of HBsAg(+) mothers, the prognosis was better in older children compared with the younger. Conclusion: The implementation of universal infant immunization for 13 years has helped to significantly improve the disease outcomes. HBV carriage in mothers and the timeliness of first dosing are important factors in the protective efficacy of HBV vaccine.
[-P-~
Efficiency of HBV vaccination for healthcare workers
A. Tanomand 2, S.H. Montazam 1 *, A. Khaki 2, A. Sani 2, M. Najari nabi 2, M. Kafshnochi 1. 1Microbiology, Bonab Islamic Azad
University, Bonab; 2Microbiology, Tabriz Medical Sciences University, Tabriz, Iran Background and Objectives: Hepatitis B is a serious disease caused by a virus that attacks the liver. HBV can cause chronic infection, cirrhosis and/or cancer of the liver. HBV vaccine prevents infection and related diseases to HBV. The aim of this study is estimating efficacy of HBV vaccine in medical group individuals. Methods: In a cross sectional study in 2004, blood samples of 240 persons, who were vaccinated compactly (1 to 6 month before), were collected. Then HBsAb were estimated by EIA method. The antibody more than 10 IU/ml seems to be protective. Negative cases were vaccinated for fourth time and have studied for HBV serologic markers. Data were analyzed by SPSS version 12. Results: The presence of HBsAb over 101U were seen in 210 persons. Therefore the efficacy of vaccine was 87.5%. The lower limit was 0, and upper limit was 542 IU. After fourth dose of vaccine, 20 persons had HBsAb over 101U, but 10 persons had negative results in the second test and 6 persons had HBsAg and Anti-HBcAb positive. Conclusion: The findings showed that vaccine efficacy was similar as in other studies (85-99%). In view of the 12.5% nonimmune subjects, it is better that storage conditions and efficiency of available vaccine will be studied. With respect to the HBsAg and Anti-HBcAb results, those subjects had past infection especially in the vaccination time. Vaccination is seriously recommended, because use of vaccine against HBV is useful, especially in endemic areas, and prevents complications of infection in the future. Also, it is recommended to measure HBV serologic markers before marriage.