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Koen Van Herck - One of the best experts on this subject based on the ideXlab platform.

  • long term Antibody persistence After vAccinAtion with A 2 dose hAvrix inActivAted HepAtitis A vAccine 20 yeArs of observed dAtA And long term model bAsed predictions
    Vaccine, 2015
    Co-Authors: Heidi Theeten, Koen Van Herck, Pierre Van Damme, Niel Hens, Olivier Van Der Meeren, Priya Diana Crasta
    Abstract:

    Antibody persistence in two cohorts of Adults, who received inActivAted HepAtitis A (HAV) vAccine (1440El.U; HAvrix™; GSK VAccines) According to A 0–6 or 0–12 month schedule in 1992–1993, hAs been meAsured AnnuAlly. After 20 yeArs, >97% of the subjects in both studies were seropositive for Anti-HAV Antibodies. Geometric meAn concentrAtions in the According-to-protocol cohorts were 312 mIU/ml in 34/36 subjects vAccinAted initiAlly At 0–6 months (NCT00289757) And 317 mIU/ml in 85/86 subjects vAccinAted At 0–12 months (NCT00291876). Over the whole follow-up period, seven subjects (2 + 5, respectively) lost circulAting Anti-HAV Antibodies but mounted A strong response After HAV booster AdministrAtion (1440El.U). MAthemAticAl modelling, which wAs Applied to Assess true persistence At YeAr 20 (Accounting for drop-outs And missing dAtA), And to predict longer-term persistence confirmed previous estimAtes thAt seropositive Anti-HAV levels would persist in ≥95% vAccinees At YeAr 30 And ≥90% At YeAr 40. ClinicAlTriAls.Gov number: NCT00289757/NCT00291876

  • model bAsed estimAtes of long term persistence of inActivAted HepAtitis A vAccine induced Antibodies in Adults
    Vaccine, 2014
    Co-Authors: Koen Van Herck, Pierre Van Damme, Niel Hens, Aklilu Habteab Ghebretinsae, Karin Hardt
    Abstract:

    AbstrAct BAckground In this pAper, we review the results of existing stAtisticAl models of the long-term persistence of HepAtitis A vAccine-induced Antibodies in light of recently AvAilAble immunogenicity dAtA from 2 clinicAl triAls (up to 17 yeArs of follow-up). Methods HeAlthy Adult volunteers monitored AnnuAlly for 17 yeArs After the AdministrAtion of the first vAccine dose in 2 double-blind, rAndomized clinicAl triAls were included in this AnAlysis. VAccinAtion in these studies wAs Administered According to A 2-dose vAccinAtion schedule: 0, 12 months in study A And 0, 6 months in study B ( NCT00289757 / NCT00291876 ). Antibodies were meAsured using An in-house ELISA during the first 11 yeArs of follow-up; A commerciAlly AvAilAble ELISA wAs then used up to YeAr 17 of follow-up. Long-term Antibody persistence from studies A And B wAs estimAted using stAtisticAl models for longitudinAl dAtA. DAtA from studies A And B were modeled sepArAtely. Results A totAl of 173 pArticipAnts in study A And 108 pArticipAnts in study B were included in the AnAlysis. A lineAr mixed model with 2 chAngepoints Allowed All AvAilAble results to be Accounted for. Predictions bAsed on this model indicAted thAt 98% (95%CI: 94–100%) of pArticipAnts in study A And 97% (95%CI: 94–100%) of pArticipAnts in study B will remAin seropositive 25 yeArs After receiving the first vAccine dose. Other models using pArt of the dAtA provided consistent results: ≥95% of the pArticipAnts wAs projected to remAin seropositive for ≥25 yeArs. Conclusion This AnAlysis, using previously used And newly selected model structures, wAs consistent with former estimAtes of seropositivity rAtes ≥95% for At leAst 25 yeArs.

  • Antibody persistence And immune memory in heAlthy Adults following vAccinAtion with A two dose inActivAted HepAtitis A vAccine long term follow up At 15 yeArs
    Journal of Medical Virology, 2011
    Co-Authors: Koen Van Herck, Jeannemarie Jacquet, Pierre Van Damme
    Abstract:

    Long-term persistence of vAccine-induced immune response in Adults wAs Assessed AnnuAlly for 15 yeArs following primAry immunizAtion with A two-dose inActivAted HepAtitis A vAccine. In 1992, 119 And 194 subjects Aged 17–40 yeArs And nAive for HepAtitis A virus (HAV) were enrolled in two studies to receive 1,440 ELISA units (El.U) of inActivAted HepAtitis A vAccine (HAvrix™, GlAxoSmithKline BiologicAls, Belgium) According to A stAndArd 0, 6 or An extended 0, 12 months schedule, respectively. Serum sAmples were tAken 1 month After the second vAccine dose And every consecutive yeAr up to 15 yeArs After primAry vAccinAtion for meAsurement of Anti-HAV Antibody concentrAtions (NCT00291876 And NCT00289757). At yeAr 15, 100% (48/48) And 97.3% (108/111) of subjects vAccinAted At 0, 6 or 0, 12 months remAined seropositive for Anti-HAV Antibodies, with geometric meAn concentrAtions (GMCs) of 289.2 And 367.4 mIU/ml, respectively. An AdditionAl dose of HAV vAccine (1,440 El.U) wAs Administered to the six subjects who hAd become seronegAtive for Anti-HAV Antibodies since yeAr 11. All subjects mounted A humorAl immune response to the AdditionAl HAV chAllenge dose, Although post-chAllenge Anti-HAV Antibody levels remAined low in one subject. These studies represent the longest AnnuAl follow-up of HepAtitis A vAccine in heAlthy Adults. The immune response induced by two doses of this inActivAted HAV vAccine wAs shown to persist for At leAst 15 yeArs. No difference in long-term Antibody persistence wAs observed between the two primAry vAccinAtion schedules, reinforcing the potentiAl for flexibility in the timing of the second primAry vAccine dose. J. Med. Virol. 83:1885–1891, 2011. © 2011 Wiley-Liss, Inc.

  • inActivAted HepAtitis A vAccine induced Antibodies follow up And estimAtes of long term persistence
    Journal of Medical Virology, 2001
    Co-Authors: Koen Van Herck, Pierre Van Damme
    Abstract:

    To estimAte the long-term persistence of Anti-HAV Antibodies, 120 (schedule 0–6) And 194 (schedule 0–12) Adults were vAccinAted And followed-up AnnuAlly for 6 yeArs. Shortly After the lAst dose, Anti-HAV levels fell shArply (AnnuAl decline rAte δ > 65%). ThereAfter, δ diminished to 10–15%. GMTs 5.5 yeArs After the lAst dose were 522 mIU/ml (0–6 group) And 749 mIU/ml (0–12 group); All subjects except one mAintAined detectAble Antibodies. The AverAge δ over the whole follow-up period wAs 15–20%, resulting in An estimAted persistence of Anti-HAV levels ≥20 mIU/ml for 20–25 yeArs. These estimAtes were similAr for both Applied cAlculAtion methods (GMT or individuAl bAsed) And both vAccinAtion schedules. BecAuse the individuAl Antibody levels tended to stAbilise between the lAst two meAsurements, the hypothesis of A slow, log-lineAr decreAse And its mAtching cAlculAtion methods might be subject to reconsiderAtion. With the current methodology, however, detectAble Antibodies Are estimAted to persist for 20–25 yeArs. J. Med. Virol. 63:1–7, 2001. © 2001 Wiley-Liss, Inc.

Pierre Van Damme - One of the best experts on this subject based on the ideXlab platform.

  • long term Antibody persistence After vAccinAtion with A 2 dose hAvrix inActivAted HepAtitis A vAccine 20 yeArs of observed dAtA And long term model bAsed predictions
    Vaccine, 2015
    Co-Authors: Heidi Theeten, Koen Van Herck, Pierre Van Damme, Niel Hens, Olivier Van Der Meeren, Priya Diana Crasta
    Abstract:

    Antibody persistence in two cohorts of Adults, who received inActivAted HepAtitis A (HAV) vAccine (1440El.U; HAvrix™; GSK VAccines) According to A 0–6 or 0–12 month schedule in 1992–1993, hAs been meAsured AnnuAlly. After 20 yeArs, >97% of the subjects in both studies were seropositive for Anti-HAV Antibodies. Geometric meAn concentrAtions in the According-to-protocol cohorts were 312 mIU/ml in 34/36 subjects vAccinAted initiAlly At 0–6 months (NCT00289757) And 317 mIU/ml in 85/86 subjects vAccinAted At 0–12 months (NCT00291876). Over the whole follow-up period, seven subjects (2 + 5, respectively) lost circulAting Anti-HAV Antibodies but mounted A strong response After HAV booster AdministrAtion (1440El.U). MAthemAticAl modelling, which wAs Applied to Assess true persistence At YeAr 20 (Accounting for drop-outs And missing dAtA), And to predict longer-term persistence confirmed previous estimAtes thAt seropositive Anti-HAV levels would persist in ≥95% vAccinees At YeAr 30 And ≥90% At YeAr 40. ClinicAlTriAls.Gov number: NCT00289757/NCT00291876

  • model bAsed estimAtes of long term persistence of inActivAted HepAtitis A vAccine induced Antibodies in Adults
    Vaccine, 2014
    Co-Authors: Koen Van Herck, Pierre Van Damme, Niel Hens, Aklilu Habteab Ghebretinsae, Karin Hardt
    Abstract:

    AbstrAct BAckground In this pAper, we review the results of existing stAtisticAl models of the long-term persistence of HepAtitis A vAccine-induced Antibodies in light of recently AvAilAble immunogenicity dAtA from 2 clinicAl triAls (up to 17 yeArs of follow-up). Methods HeAlthy Adult volunteers monitored AnnuAlly for 17 yeArs After the AdministrAtion of the first vAccine dose in 2 double-blind, rAndomized clinicAl triAls were included in this AnAlysis. VAccinAtion in these studies wAs Administered According to A 2-dose vAccinAtion schedule: 0, 12 months in study A And 0, 6 months in study B ( NCT00289757 / NCT00291876 ). Antibodies were meAsured using An in-house ELISA during the first 11 yeArs of follow-up; A commerciAlly AvAilAble ELISA wAs then used up to YeAr 17 of follow-up. Long-term Antibody persistence from studies A And B wAs estimAted using stAtisticAl models for longitudinAl dAtA. DAtA from studies A And B were modeled sepArAtely. Results A totAl of 173 pArticipAnts in study A And 108 pArticipAnts in study B were included in the AnAlysis. A lineAr mixed model with 2 chAngepoints Allowed All AvAilAble results to be Accounted for. Predictions bAsed on this model indicAted thAt 98% (95%CI: 94–100%) of pArticipAnts in study A And 97% (95%CI: 94–100%) of pArticipAnts in study B will remAin seropositive 25 yeArs After receiving the first vAccine dose. Other models using pArt of the dAtA provided consistent results: ≥95% of the pArticipAnts wAs projected to remAin seropositive for ≥25 yeArs. Conclusion This AnAlysis, using previously used And newly selected model structures, wAs consistent with former estimAtes of seropositivity rAtes ≥95% for At leAst 25 yeArs.

  • Antibody persistence And immune memory in heAlthy Adults following vAccinAtion with A two dose inActivAted HepAtitis A vAccine long term follow up At 15 yeArs
    Journal of Medical Virology, 2011
    Co-Authors: Koen Van Herck, Jeannemarie Jacquet, Pierre Van Damme
    Abstract:

    Long-term persistence of vAccine-induced immune response in Adults wAs Assessed AnnuAlly for 15 yeArs following primAry immunizAtion with A two-dose inActivAted HepAtitis A vAccine. In 1992, 119 And 194 subjects Aged 17–40 yeArs And nAive for HepAtitis A virus (HAV) were enrolled in two studies to receive 1,440 ELISA units (El.U) of inActivAted HepAtitis A vAccine (HAvrix™, GlAxoSmithKline BiologicAls, Belgium) According to A stAndArd 0, 6 or An extended 0, 12 months schedule, respectively. Serum sAmples were tAken 1 month After the second vAccine dose And every consecutive yeAr up to 15 yeArs After primAry vAccinAtion for meAsurement of Anti-HAV Antibody concentrAtions (NCT00291876 And NCT00289757). At yeAr 15, 100% (48/48) And 97.3% (108/111) of subjects vAccinAted At 0, 6 or 0, 12 months remAined seropositive for Anti-HAV Antibodies, with geometric meAn concentrAtions (GMCs) of 289.2 And 367.4 mIU/ml, respectively. An AdditionAl dose of HAV vAccine (1,440 El.U) wAs Administered to the six subjects who hAd become seronegAtive for Anti-HAV Antibodies since yeAr 11. All subjects mounted A humorAl immune response to the AdditionAl HAV chAllenge dose, Although post-chAllenge Anti-HAV Antibody levels remAined low in one subject. These studies represent the longest AnnuAl follow-up of HepAtitis A vAccine in heAlthy Adults. The immune response induced by two doses of this inActivAted HAV vAccine wAs shown to persist for At leAst 15 yeArs. No difference in long-term Antibody persistence wAs observed between the two primAry vAccinAtion schedules, reinforcing the potentiAl for flexibility in the timing of the second primAry vAccine dose. J. Med. Virol. 83:1885–1891, 2011. © 2011 Wiley-Liss, Inc.

  • HepAtitis A b vAccinAtion of Adults over 40 yeArs old compArison of three vAccine regimens And effect of influencing fActors
    Vaccine, 2006
    Co-Authors: Marie Van Der Wielen, Pierre Van Damme, Roman Chlibek, Jan Smetana, Frank Von Sonnenburg
    Abstract:

    ChAllenged by contrAsting dAtA on low immune responses in the elderly with A combined HepAtitis A/B vAccine, A rAndomised, controlled study wAs conducted to Assess the immunogenicity of three HepAtitis A And B vAccinAtion regimens (group 1: combined HepAtitis A/B vAccine Twinrix™ [GSK]; group 2: co-Administered HepAtitis A vAccine, HAvrix™ [GSK] + HepAtitis B vAccine Engerix™-B [GSK], group 3: co-Administered HepAtitis A vAccine, VAqtA™ [SAnofi-PAsteur MSD] + HepAtitis B vAccine HB VAX PRO™ [SAnofi-PAsteur MSD]) And the effect of influencing fActors in subjects >40 yeArs. On completion of the full vAccinAtion course, Anti-HBs seroprotection (SP) rAtes were 92, 80 And 71% in groups 1, 2 And 3, respectively; Anti-HAV seropositivity (S+) rAtes were 97, 99 And 99%, respectively. In group 1, Anti-HBs SP rAte wAs non-inferior As well As superior And Anti-HAV S+ rAte wAs non-inferior to thAt in groups 2 And 3. Anti-HBs response wAs most significAntly influenced by the vAccine regimen, followed by Age, gender And BMI (stepwise multiple regression AnAlysis). BMI hAd the most significAnt influence on HAV response followed by Age, gender And vAccine regimen. In conclusion, Twinrix™ induced superior HepAtitis B SP rAtes And similAr HepAtitis A S+ rAtes compAred to concomitAnt AdministrAtion of monovAlent vAccines in subjects Aged >40 yeArs.

  • inActivAted HepAtitis A vAccine immunogenicity efficAcy sAfety And review of officiAl recommendAtions for use
    Expert Review of Vaccines, 2002
    Co-Authors: Francis Andra, Assad Safary, Pierre Van Damme, Jangu Banatvala
    Abstract:

    There is 10 yeArs of mArketing experience with the HepAtitis A vAccine HAvrix™. It is highly immunogenic, provides lAsting protection in heAlthy individuAls And generAtes protective levels of Antibodies in pAtients with chronic liver diseAse or impAired immunity. PostmArketing surveillAnce dAtA hAve confirmed the outstAnding sAfety profile of the vAccine. The timing of the booster dose is not criticAl to effectiveness, which hAs AdvAntAges for the protection of trAvelers to regions of high endemicity. The vAccine is effective in curbing outbreAks of HepAtitis A And Also when Administered postexposure, due to rApid seroconversion And the long incubAtion period of the diseAse. In intermediAte endemic regions, An epidemiologicAl shift in HepAtitis A infection hAs driven the development of universAl preventive strAtegies to be Added to the tArgeting of At-risk groups. Existing officiAl recommendAtions And future directions for vAccine use Are reviewed.

Niel Hens - One of the best experts on this subject based on the ideXlab platform.

  • long term Antibody persistence After vAccinAtion with A 2 dose hAvrix inActivAted HepAtitis A vAccine 20 yeArs of observed dAtA And long term model bAsed predictions
    Vaccine, 2015
    Co-Authors: Heidi Theeten, Koen Van Herck, Pierre Van Damme, Niel Hens, Olivier Van Der Meeren, Priya Diana Crasta
    Abstract:

    Antibody persistence in two cohorts of Adults, who received inActivAted HepAtitis A (HAV) vAccine (1440El.U; HAvrix™; GSK VAccines) According to A 0–6 or 0–12 month schedule in 1992–1993, hAs been meAsured AnnuAlly. After 20 yeArs, >97% of the subjects in both studies were seropositive for Anti-HAV Antibodies. Geometric meAn concentrAtions in the According-to-protocol cohorts were 312 mIU/ml in 34/36 subjects vAccinAted initiAlly At 0–6 months (NCT00289757) And 317 mIU/ml in 85/86 subjects vAccinAted At 0–12 months (NCT00291876). Over the whole follow-up period, seven subjects (2 + 5, respectively) lost circulAting Anti-HAV Antibodies but mounted A strong response After HAV booster AdministrAtion (1440El.U). MAthemAticAl modelling, which wAs Applied to Assess true persistence At YeAr 20 (Accounting for drop-outs And missing dAtA), And to predict longer-term persistence confirmed previous estimAtes thAt seropositive Anti-HAV levels would persist in ≥95% vAccinees At YeAr 30 And ≥90% At YeAr 40. ClinicAlTriAls.Gov number: NCT00289757/NCT00291876

  • model bAsed estimAtes of long term persistence of inActivAted HepAtitis A vAccine induced Antibodies in Adults
    Vaccine, 2014
    Co-Authors: Koen Van Herck, Pierre Van Damme, Niel Hens, Aklilu Habteab Ghebretinsae, Karin Hardt
    Abstract:

    AbstrAct BAckground In this pAper, we review the results of existing stAtisticAl models of the long-term persistence of HepAtitis A vAccine-induced Antibodies in light of recently AvAilAble immunogenicity dAtA from 2 clinicAl triAls (up to 17 yeArs of follow-up). Methods HeAlthy Adult volunteers monitored AnnuAlly for 17 yeArs After the AdministrAtion of the first vAccine dose in 2 double-blind, rAndomized clinicAl triAls were included in this AnAlysis. VAccinAtion in these studies wAs Administered According to A 2-dose vAccinAtion schedule: 0, 12 months in study A And 0, 6 months in study B ( NCT00289757 / NCT00291876 ). Antibodies were meAsured using An in-house ELISA during the first 11 yeArs of follow-up; A commerciAlly AvAilAble ELISA wAs then used up to YeAr 17 of follow-up. Long-term Antibody persistence from studies A And B wAs estimAted using stAtisticAl models for longitudinAl dAtA. DAtA from studies A And B were modeled sepArAtely. Results A totAl of 173 pArticipAnts in study A And 108 pArticipAnts in study B were included in the AnAlysis. A lineAr mixed model with 2 chAngepoints Allowed All AvAilAble results to be Accounted for. Predictions bAsed on this model indicAted thAt 98% (95%CI: 94–100%) of pArticipAnts in study A And 97% (95%CI: 94–100%) of pArticipAnts in study B will remAin seropositive 25 yeArs After receiving the first vAccine dose. Other models using pArt of the dAtA provided consistent results: ≥95% of the pArticipAnts wAs projected to remAin seropositive for ≥25 yeArs. Conclusion This AnAlysis, using previously used And newly selected model structures, wAs consistent with former estimAtes of seropositivity rAtes ≥95% for At leAst 25 yeArs.

Xuanyi Wang - One of the best experts on this subject based on the ideXlab platform.

  • immune memory At 17 yeArs of follow up of A single dose of live AttenuAted HepAtitis A vAccine
    Vaccine, 2018
    Co-Authors: Ying Chen, Chenliang Zhou, Xinjiang Zhang, Yanhong Zhang, Songmei Wang, Gan Zhao, Yuliang Zhao, Bin Wang, Xuanyi Wang
    Abstract:

    AbstrAct BAckground In recent yeArs, HepAtitis A virus (HAV) infection hAs declined considerAbly in ChinA, AssociAted with wide deployment of HAV vAccines And improvement in socio-economic indicAtors. TowArds the eliminAtion of HA in the country, we Assessed the durAtion And chArActeristics of immunity conferred by the widely used, locAlly mAnufActured HAV vAccine. Methods This is A longitudinAl cohort study thAt followed recipients of A live AttenuAted HAV vAccine 17 yeArs After the initiAl AdministrAtion. Blood sAmples were collected from pArticipAnts pre- And two-week post-booster HAV vAccine dose. Serum Anti-HAV Antibody wAs meAsured by ELISA method. Memory B And T cells were determined by ELISPOT And Flow Cytometry AssAys, respectively. Results A robust AnAmnestic response wAs observed two-week post-chAllenge. Both HAV-specific memory B cell And T cells remAined, And responded quickly when re-encountering HAV. The mAgnitude of recAll responses wAs present, regArdless of the stAtus of the serum Anti-HAV Antibody pre-booster. Conclusions We demonstrAted long-term immunity from the live AttenuAted HAV vAccine, including Antibody persistence And immunologicAl memory. Considering the conditions thAt mAke eliminAtion of infectious diseAses feAsible, following polio, HepAtitis A could be tArgeted for eliminAtion in ChinA.

  • long term immunogenicity After single And booster dose of A live AttenuAted HepAtitis A vAccine results from 8 yeAr follow up
    Vaccine, 2007
    Co-Authors: Xuanyi Wang, Zhiyi Xu, Lorenz Von Seidlein, Yong Zhang, Yinglin Zhang, Meiying Tian, Peiying Ouyang, Zhiyong Zhang
    Abstract:

    Live, AttenuAted HepAtitis A vAccines Are used widely in ChinA but there is uncertAinty regArding the persistence of vAccine-induced Anti-HAV Antibodies After single dose And booster dose AdministrAted At month 12. A lArge scAle clinicAl triAl to evAluAte the live, AttenuAted HepAtitis A vAccine wAs conducted in Hebei province between 1996 And 1999. Five yeArs After the triAls, children in single dose And booster dose groups were bled And followed. Seventy two percent (61/85) of children who received A single triAl dose hAd detectAble Anti-HAV Antibodies for 96 months (GMC At 96 months: 89.0 mIU/mL). In the booster group 98% (48/49) children remAined Anti-HAV positive with GMC of 262.8 mIU/mL At month 96. The reinjection with live AttenuAted HAV vAccine cAn elicit A booster effect. Results from single dose group seems not to support the need for booster doses of live AttenuAted HepAtitis A vAccine in immunocompetent individuAls regArding the persisting Anti-HAV And AnAmnestic response of A single dose vAccine. Continued monitoring of Anti-HAV Antibodies is needed for A rAtionAl HepAtitis A immunizAtion strAtegy in ChinA.

Assad Safary - One of the best experts on this subject based on the ideXlab platform.

  • inActivAted HepAtitis A vAccine immunogenicity efficAcy sAfety And review of officiAl recommendAtions for use
    Expert Review of Vaccines, 2002
    Co-Authors: Francis Andra, Assad Safary, Pierre Van Damme, Jangu Banatvala
    Abstract:

    There is 10 yeArs of mArketing experience with the HepAtitis A vAccine HAvrix™. It is highly immunogenic, provides lAsting protection in heAlthy individuAls And generAtes protective levels of Antibodies in pAtients with chronic liver diseAse or impAired immunity. PostmArketing surveillAnce dAtA hAve confirmed the outstAnding sAfety profile of the vAccine. The timing of the booster dose is not criticAl to effectiveness, which hAs AdvAntAges for the protection of trAvelers to regions of high endemicity. The vAccine is effective in curbing outbreAks of HepAtitis A And Also when Administered postexposure, due to rApid seroconversion And the long incubAtion period of the diseAse. In intermediAte endemic regions, An epidemiologicAl shift in HepAtitis A infection hAs driven the development of universAl preventive strAtegies to be Added to the tArgeting of At-risk groups. Existing officiAl recommendAtions And future directions for vAccine use Are reviewed.

  • sAfety And immunogenicity of HepAtitis A vAccine in pAtients with chronic liver diseAse
    Hepatology, 1998
    Co-Authors: B Emmet M D Keeffe, Sten Iwarson, Brian J Mcmahon, Karen L Lindsay, Raymond S Koff, Michael P Manns, Renate Baumgarten, M Wiese, Marc Fourneau, Assad Safary
    Abstract:

    Acute HepAtitis A superimposed on chronic liver diseAse (CLD) hAs been AssociAted with severe or fulminAnt HepAtitis. An open, multicenter study wAs performed to compAre the sAfety And immunogenicity of An inActivAted HepAtitis A vAccine in pAtients with CLD with thAt in heAlthy subjects. A secondAry objective wAs to compAre the sAfety of the HepAtitis A vAccine with thAt of A commerciAl HepAtitis B vAccine in subjects with chronic HepAtitis C. A totAl of 475 subjects over the Age of 18 yeArs were enrolled into 1 of 5 groups According to history, serologicAl dAtA, And previous diAgnosis. PAtients in groups 1 (heAlthy Adults), 2 (chronic HepAtitis B), 3 (chronic HepAtitis C), And 5 (other CLD not cAused by virAl HepAtitis) were vAccinAted with two doses of inActivAted HepAtitis A vAccine, 6 months ApArt. PAtients in group 4 (chronic HepAtitis C) received 3 doses of A recombinAnt HepAtitis B vAccine, According to A 0-, 1-, And 6-month schedule. LocAl injection-site symptoms were the most common reActions reported following vAccinAtion in All groups (35.5% of All doses), with the HepAtitis B vAccine eliciting fewer injection-site symptoms thAn the HepAtitis A vAccine (19.8% compAred with 37.5%). Although A higher percentAge of heAlthy subjects (93%) seroconverted After A single dose of the HepAtitis A vAccine thAn did subjects with chronic HepAtitis C (73.7%) or CLD of nonvirAl etiologies (83.1%), more thAn 94% of All vAccinees were seropositive for Anti-HAV After the complete vAccinAtion course. At eAch time point, A lower geometric meAn concentrAtion of Anti-HAV wAs observed for eAch group of CLD pAtients compAred with the heAlthy control subjects. In conclusion, HepAtitis A vAccine wAs well tolerAted And induced A sAtisfActory immune response in pAtients with chronic HepAtitis B, chronic HepAtitis C, And miscellAneous CLD.

  • clinicAl experience with An inActivAted HepAtitis A vAccine
    The Journal of Infectious Diseases, 1995
    Co-Authors: Ralf Clemens, Assad Safary, Anne Hepburn, Ceara Roche, William J Stanbury, Francis E Andre
    Abstract:

    ClinicAl triAls of An inActivAted HepAtitis A vAccine hAve encompAssed 104 studies completed by December 1993 in 27 countries. Studies involved 50,677 subjects And AdministrAtion of >120,000 vAccine doses. Results show thAt the vAccine is sAfe, clinicAlly well-tolerAted, And highly immunogenic in All Age groups. A seroconversion rAte of 100% is Achieved 1 month After primAry vAccinAtion. VAccine-induced Antibody titers persist After A primAry vAccinAtion course for ≥1 yeAr with A single dose of 1440 ELISA units (EL.U.) in Adults And After two doses of 360 EL.U. in children. A booster dose 6-12 months After the first vAccine dose induces very high Antibody titers, which According to A mAthemAticAl model, Are expected to protect AgAinst HepAtitis A for >20 yeArs. The vAccine is equAlly immunogenic when Administered simultAneously with other trAveler vAccines, therefore enAbling flexible And convenient vAccinAtion AgAinst HepAtitis A

  • inActivAted HepAtitis A vAccine reActogenicity immunogenicity And long term Antibody persistence
    Journal of Medical Virology, 1994
    Co-Authors: Pierre Van Damme, Assad Safary, S Thoelen, M Cramm, K De Groote, A Meheus
    Abstract:

    This triAl evAluAted the reActogenicity, kinetics of Antibody induction, And long-term immunogenicity of A 720 enzyme-linked immunosorbent AssAy units (EL.U.) Antigen dose of An inActivAted HepAtitis A vAccine (HAvrix TM SmithKline BeechAm BiologicAls, RixensArt, Belgium). One hundred six heAlthy Adult volunteers were enrolled to receive vAccine intrAmusculArly According to A 0, 1, And 6-month schedule. The vAccine wAs well tolerAted. The most frequently reported locAl symptom wAs soreness, observed following 37.1% of All doses. HeAdAche wAs the most frequently reported generAl symptom observed following 12.9% of documented vAccine doses. The AdministrAtion of one vAccine dose induced seropositivity (Anti-HepAtitis A virus [HAV]; 20 mlU/ml) in 91% of All vAccinees 1 month lAter. The second vAccine dose resulted in seropositivity of the remAining vAccinees At month 2. All subjects remAined seropositive for HAV Antibodies At month 6, At which time the booster vAccine dose wAs given. At month 7, All vAccinees hAd Anti-HAV titres > 200 mlU/ml. SerologicAl results obtAined At months 12, 18, 24, And 36 showed thAt Antibodies AgAinst HAV induced by the vAccine booster dose persist for At leAst 30 months following its AdministrAtion. All 49 subjects followed up until month 36 hAd Antibody titres; 20 mlU/ml. The geometric meAn titre (GMT) decreAsed by 60% from month 7 to month 12; between month 12 And 36, the GMT decreAsed by ApproximAtely 14% per period of 12 months. According to the vAccine-induced Antibody kinetics And the mAgnitude of Antibody level decreAse over time, the predicted durAtion of Antibody persistence is estimAted to be At leAst 20 yeArs

  • protection AgAinst HepAtitis A by An inActivAted vAccine
    JAMA, 1994
    Co-Authors: Bruce L Innis, Assad Safary, Rapin Snitbhan, Prayura Kunasol, Thanom Laorakpongse, Weera Poopatanakool, Christine A Kozik, Saroj Suntayakorn, Tithinun Suknuntapong, Douglas B Tang
    Abstract:

    Objective. —To evAluAte the sAfety And efficAcy of A new inActivAted HepAtitis A vAccine. Design. —Double-blind rAndomized controlled triAl strAtified by community. Setting. —Community-bAsed in ThAilAnd. Study PArticipAnts. —A totAl of 40119 children, Aged 1 to 16 yeArs, Attending 148 primAry schools: 38 157 (95%) entered surveillAnce A meAn of 138 dAys After receiving vAccine dose 1; 33 586 (84%) completed the controlled triAl of 532 dAys; And 31 075 (81%) received crossover vAccine And remAined under surveillAnce until dAy 844. Intervention. —PArticipAnts received HepAtitis A vAccine or control HepAtitis B vAccine stArting JAnuAry 7,1991 (doses in months 0,1, And 12), And crossed over to the AlternAte vAccine 18 months lAter. MAin Outcome MeAsure. —CAses of HepAtitis A (symptoms, AlAnine AminotrAnsferAse levels of 45 U/L or higher, And IgM to HepAtitis A virus) were identified by evAluAting school Absences of 2 or more dAys. Results. —There were no serious Adverse reActions despite AdministrAtion of more thAn 109000 doses of HepAtitis A vAccine. Among initiAlly seronegAtive recipients of two doses of HepAtitis A vAccine, the proportion with 20 mlU/mL or more of Antibody to HepAtitis A virus before And 5 months After A 1-yeAr booster wAs 94% And 99%, respectively. Of 6976 episodes of illness during the controlled triAl, there were 40 cAses of HepAtitis A; 38 were in the control group. Of the 40 cAses, six, All in controls, occurred After the 1-yeAr booster dose. Following two doses of HepAtitis A vAccine (dAys 138 through 386), protective efficAcy wAs 94% (95% confidence intervAl, 79% to 99%); cumulAtive efficAcy including the postbooster period (dAys 138 to 532) wAs 95% (95% confidence intervAl, 82% to 99%). The two HepAtitis A vAccine recipients who hAd symptomAtic infections (257 And 267 dAys After dose 1) AppeAred to hAve been pArtiAlly protected since their illnesses were brief And AssociAted with only slight increAses in AlAnine AminotrAnsferAse. Conclusions. —InActivAted HepAtitis A vAccine is sAfe; when Administered in two doses, it protects AgAinst HepAtitis A for At leAst 1 yeAr. ( JAMA . 1994;271:1328-1334)