human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Children are a reservoir of hepatitis A virus and must be considered as primary targets of any immunization strategy . The safety and immunogenicity were evaluated for a new formulation of an inactivated hepatitis A vaccine , Avaxim 80 units , containing one-half the antigen dose of the adult formulation . METHODS The safety of two doses of this vaccine given 6 months apart was evaluated in an open study in 537 Argentinean children 12 months to 15 years old . Immunogenicity was evaluated at Weeks 0 , 2 , 24 and 27 in a subgroup of 120 subjects . RESULTS Two weeks after the first vaccine dose , > 99 % of initially seronegative children had seroconverted ( titers > or = 20 mIU/ml ) , with a geometric mean titer of 98.5 mIU/ml . Before booster at 24 weeks all subjects had seroconverted . A strong anamnestic response was observed after the second dose at which time the geometric mean titer had increased > 35-fold , and antibody titers were consistent with long term protection . Immediate adverse reactions were observed in 3 of 537 ( 0.6 % ) subjects after the first dose . Local reactions were mild and transient and did not increase with subsequent doses . Among the systemic events reported during the 7-day follow-up period , 37 cases of fever after the first dose and 22 cases after the second dose were reported . Only 3 cases of fever were clearly related to vaccination ( < or = 38.2 degrees C ) after the first injection , all of which subsided in less than 1 day . CONCLUSIONS This study demonstrated the safety and immunogenicity of a pediatric formulation of hepatitis A vaccine in children ages 12 months to 15 years in healthy children ages 12 to 47 months An Hasidic Jewish community has experienced recurrent hepatitis A outbreaks since 1980 . To assess risk factors for illness during a 1985 - 6 outbreak , the authors review ed case records and r and omly selected 93 households for an interview and serologic survey . In the outbreak , 117 cases of hepatitis A were identified , with the highest attack rate ( 4.2 % ) among 3 - 5 year olds . Among the survey households , the presence of 3 - 5 year olds was the only risk factor that increased a household 's risk of hepatitis A ( indeterminant relative risk , P = 0.02 ) . Furthermore , case households from the outbreak were more likely to have 3 - 5 years olds than were control households from the survey ( odds ratio = 16.4 , P < 0.001 ) . Children 3 - 5 years old were more likely to have hepatitis A and may have been the most frequent transmitters of hepatitis A in this community . Hepatitis A vaccination of 3 - 5 year olds can protect this age group and might prevent future outbreaks in the community ABSTRACT Background : Inactivated vaccines for hepatitis A virus ( HAV ) infection are widely used in China . Mass vaccination programs drive the need for data on long-term persistence of vaccine-induced protection . Methods : A prospect i ve , r and omized , open-label clinical trial was conducted to compare geometric mean concentrations ( GMCs ) and seroconversion rates ( SRs ) of anti-HAV antibody elicited by the inactivated vaccines Healive and Havrix for 5 y post immunization , in which 400 healthy children were r and omly assigned in a 3:1 ratio to receive 2 doses of Healive or Havrix at 0 and 6 month . Anti-HAV antibody concentration was detected by microparticle enzyme immunoassay ( MEIA ) during the study . Furthermore , an attempt was made to predict persistence of protective immunogenicity by using a suitable statistical model . Results : The GMCs were significantly higher after vaccination with Healive than after Havrix as comparator vaccine at 1 , 6 , 7 , 18 , 30 , 42 , 54 and 66 month ( P < 0.01 ) with the peak point at 7 month ( 3427.2 mIU/ml for Healive and 1441.9 mIU/ml for Comparator ) . Similarly significant differences of SRs were found between the 2 groups at 1 and 6 month ( P < 0.01 ) . Afterwards , the SRs of both groups reached 100 % at 7 month and did not decline until 66 month(99.1 % for Healive and 97.5 % for Comparator ) . A linear mixed model with a change point at 18 month(Model 3 ) was found to be suitable to predict persistence of protective immunogenicity induced by vaccines . It was estimated that the duration of protection for Healive was at least 20 y with a lower limit of GMC 95 % confidence interval ( CI ) no less than 20 mIU/mL. Conclusions : Compared with Havrix , the new preservative-free inactivated hepatitis A vaccine ( Healive ) in 2 doses showed better persistence of antibody concentrations for 5 y after full-course immunization among children and the persistence of protective immunogenicity was estimated for at least 20 Background : The aim of this open-label , active-controlled , parallel group , phase 2 follow-up study was to assess the long-term immunogenicity of Epaxal Junior , the pediatric dose of an aluminum-free virosomal inactivated hepatitis A virus ( HAV ) vaccine , in children receiving routine childhood vaccines ( RCV ) . Methods : Healthy children ( 12–15 months old , ≥8 kg weight ) were r and omized ( 1:1:1 ) to group A : Epaxal Junior + RCV ( day 1 ) ; group B : Epaxal Junior ( day 1 ) + RCV ( day 29 ) and group C : Havrix 720 + RCV ( day 1 ) . All 3 groups received 2 doses of HAV vaccines 6 months apart . Children who completed the primary study were followed up from 18 months to 7.5 years post booster . Results : Of 291/327 r and omized children who had completed the primary study , 157 were followed for the 7.5-year analysis ( group A : 50 ; group B : 54 ; and group C : 53 ) . Of these , 152 children  had protective levels of anti-HAV antibodies [ ≥10 mIU/mL ; 98 % ( group A ) ; 96.3 % ( group B ) ; 96.2 % ( group C ) ] . Anti-HAV geometric mean concentrations were similar in groups A and B at all the time points ( 1.5- , 2.5- , 3.5- , 5.25- and 7.5-year time point ) but slightly lower in group C. Predictions of the median duration of persistence of seroprotective antibody levels , using the linear mixed model were similar in all groups : ( group A : 19.1 years , group B : 18.7 years , group C : 17.3 years ) . Conclusions : Immunization with Epaxal Junior administered with RCVs at 12 months elicited protective response beyond 7.5 years in almost all children . Assessing the kinetic of anti-HAV antibody titers decline over time , the moment to reach antibody concentrations below the accepted protective level may occur earlier than previously estimated The effect of passively transferred maternal antibody to hepatitis A virus ( anti‐HAV ) on the duration of seropositivity after hepatitis A vaccination during infancy and early childhood is unclear . We obtained levels of anti‐HAV at intervals through age 15‐16 years among three groups of Alaskan Native children who initiated a two‐dose inactivated hepatitis A vaccination series at ages 6 months ( group 1 ) , 12 months ( group 2 ) , and 15 months ( group 3 ) , each group r and omized according to maternal anti‐HAV status . Seropositivity ( anti‐HAV ≥20 mIU/mL ) 30 years after the second vaccine dose among the three groups was predicted using a r and om effects model . One hundred eighty‐three children participated in the study ; follow‐up did not differ significantly by vaccine group or maternal anti‐HAV status . Although the frequency of seropositivity among all participants through age 10 years was high ( 100 % among groups 2 and 3 and > 90 % among group 1 ) , there was a decrease thereafter through age 15‐16 years among group 1 children , who initiated vaccination at age 6 months ( 50%‐75 % ) , and among maternal anti‐HAV‐positive children in groups 2 and 3 ( 67%‐87 % ) , who initiated vaccination at ages 12 months and 15 months , respectively . Nonetheless , the model indicated that anti‐HAV seropositivity should persist for ≥30 years after vaccination in 64 % of all participants ; among those seropositive at age 15‐16 years , 84 % were predicted to remain so for ≥30 years . Conclusion : Most children vaccinated during early childhood available for sampling maintained seropositivity through age 15‐16 years ; however , seropositivity was less frequent among those starting vaccination at age 6 months and among maternal antibody‐positive participants who started vaccination at age 12 months or 15 months ; overall , our findings support current vaccine recommendations and continued follow‐up of this cohort . ( Hepatology 2016;63:703–711 Persistence of seropositivity conferred by hepatitis A vaccine administered to children < 2 years of age is unknown and passively transferred maternal antibodies to hepatitis A virus ( maternal anti‐HAV ) may lower the infant 's immune response to the vaccine . One hundred ninety‐seven infants and young children were r and omized into three groups to receive a two‐dose hepatitis A vaccine : group 1 at 6 and 12 months , group 2 at 12 and 18 months , and group 3 at 15 and 21 months of age . Within each group , infants were r and omized by maternal anti‐HAV status  . Anti‐HAV levels were measured at 1 and 6 months and at 3 , 5 , 7 , and 10 years after the second dose of hepatitis A vaccination . Children in all groups had evidence of seroprotection ( > 10 mIU/mL ) at 1 month after the second dose . At 10 years , all children retained seroprotective anti‐HAV levels except for only 7 % and 11 % of children in group 1 born to anti‐HAV – negative and anti‐HAV – positive mothers , respectively , and 4 % of group 3 children born to anti‐HAV – negative mothers . At 10 years , children born to anti‐HAV – negative mothers in group 3 had the highest geometric mean concentration ( GMC ) ( 97 mIU/mL ; 95 % confidence interval , 71‐133 mIU/mL ) and children born to anti‐HAV – positive mothers in group 1 had the lowest GMC ( 29 mIU/mL ; 95 % confidence interval , 20‐40 mIU/mL ) . Anti‐HAV levels through 10 years of age correlated with initial peak anti‐HAV levels ( tested at 1 month after the second dose ) . Conclusion : The seropositivity induced by hepatitis A vaccine given to children < 2 years of age persists for at least 10 years regardless of presence of maternal anti‐HAV . ( HEPATOLOGY 2012 OBJECTIVE To evaluate the safety , immunogenicity and fit dosage of Healive inactivated hepatitis A vaccine ( HAV ) in children . METHODS A total of 85 susceptible aged 4 - 10 years with HAV seronegative children , had been enrolled from two adjacent villages in a county . The volunteers were r and omized allocated into two groups and to receive a priming dose of 250 U/0.5 ml/dose or 500 U/1.0 ml/dose of Healive vaccine , produced by Sinovac Biotech Co , Ltd. A booster of the same dose was given at 12th month . Local and systemic side effects were examined and seroconversion rate as well as geometric mean titers of anti-HAV antibody were tested at 3-week , 12-month after the primary dose and at 1 month after the booster dose . RESULTS The vaccine was well tolerated in both groups . At 21 days after the primary dose , the seroconversion rates were 94.4 % , 100.0 % and geometric mean titers ( GMT ) were 195 mIU/ml and 370 mIU/ml in 250 U and 500 U groups respectively . At 12 months after the primary dose , the seroconversion rate of anti-HAV was 100.0 % , and GMT raised to 361 mIU/ml , 456 mIU/ml ( P > 0.05 ) respectively . One month after the booster dose , GMT raised to 14 893 mIU/ml , 21 696 mIU/ml . CONCLUSION GMT of the 0 , 12 month schedule was higher than other schedule after the booster vaccination . The Healive inactivated vaccine can be used for emergency vaccination . The Healive inactivated vaccine produced by Sinovac Company Ltd was safe and highly immunogenic . Two hundred and fifty U/dose was considered appropriate for children OBJECTIVE To evaluate the safety and efficacy of a new inactiv 
    Output:
    
agent
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Children are a reservoir of hepatitis A virus and must be considered as primary targets of any immunization strategy . The safety and immunogenicity were evaluated for a new formulation of an inactivated hepatitis A vaccine , Avaxim 80 units , containing one-half the antigen dose of the adult formulation . METHODS The safety of two doses of this vaccine given 6 months apart was evaluated in an open study in 537 Argentinean children 12 months to 15 years old . Immunogenicity was evaluated at Weeks 0 , 2 , 24 and 27 in a subgroup of 120 subjects . RESULTS Two weeks after the first vaccine dose , > 99 % of initially seronegative children had seroconverted ( titers > or = 20 mIU/ml ) , with a geometric mean titer of 98.5 mIU/ml . Before booster at 24 weeks all subjects had seroconverted . A strong anamnestic response was observed after the second dose at which time the geometric mean titer had increased > 35-fold , and antibody titers were consistent with long term protection . Immediate adverse reactions were observed in 3 of 537 ( 0.6 % ) subjects after the first dose . Local reactions were mild and transient and did not increase with subsequent doses . Among the systemic events reported during the 7-day follow-up period , 37 cases of fever after the first dose and 22 cases after the second dose were reported . Only 3 cases of fever were clearly related to vaccination ( < or = 38.2 degrees C ) after the first injection , all of which subsided in less than 1 day . CONCLUSIONS This study demonstrated the safety and immunogenicity of a pediatric formulation of hepatitis A vaccine in children ages 12 months to 15 years in healthy children ages 12 to 47 months An Hasidic Jewish community has experienced recurrent hepatitis A outbreaks since 1980 . To assess risk factors for illness during a 1985 - 6 outbreak , the authors review ed case records and r and omly selected 93 households for an interview and serologic survey . In the outbreak , 117 cases of hepatitis A were identified , with the highest attack rate ( 4.2 % ) among 3 - 5 year olds . Among the survey households , the presence of 3 - 5 year olds was the only risk factor that increased a household 's risk of hepatitis A ( indeterminant relative risk , P = 0.02 ) . Furthermore , case households from the outbreak were more likely to have 3 - 5 years olds than were control households from the survey ( odds ratio = 16.4 , P < 0.001 ) . Children 3 - 5 years old were more likely to have hepatitis A and may have been the most frequent transmitters of hepatitis A in this community . Hepatitis A vaccination of 3 - 5 year olds can protect this age group and might prevent future outbreaks in the community ABSTRACT Background : Inactivated vaccines for hepatitis A virus ( HAV ) infection are widely used in China . Mass vaccination programs drive the need for data on long-term persistence of vaccine-induced protection . Methods : A prospect i ve , r and omized , open-label clinical trial was conducted to compare geometric mean concentrations ( GMCs ) and seroconversion rates ( SRs ) of anti-HAV antibody elicited by the inactivated vaccines Healive and Havrix for 5 y post immunization , in which 400 healthy children were r and omly assigned in a 3:1 ratio to receive 2 doses of Healive or Havrix at 0 and 6 month . Anti-HAV antibody concentration was detected by microparticle enzyme immunoassay ( MEIA ) during the study . Furthermore , an attempt was made to predict persistence of protective immunogenicity by using a suitable statistical model . Results : The GMCs were significantly higher after vaccination with Healive than after Havrix as comparator vaccine at 1 , 6 , 7 , 18 , 30 , 42 , 54 and 66 month ( P < 0.01 ) with the peak point at 7 month ( 3427.2 mIU/ml for Healive and 1441.9 mIU/ml for Comparator ) . Similarly significant differences of SRs were found between the 2 groups at 1 and 6 month ( P < 0.01 ) . Afterwards , the SRs of both groups reached 100 % at 7 month and did not decline until 66 month(99.1 % for Healive and 97.5 % for Comparator ) . A linear mixed model with a change point at 18 month(Model 3 ) was found to be suitable to predict persistence of protective immunogenicity induced by vaccines . It was estimated that the duration of protection for Healive was at least 20 y with a lower limit of GMC 95 % confidence interval ( CI ) no less than 20 mIU/mL. Conclusions : Compared with Havrix , the new preservative-free inactivated hepatitis A vaccine ( Healive ) in 2 doses showed better persistence of antibody concentrations for 5 y after full-course immunization among children and the persistence of protective immunogenicity was estimated for at least 20 Background : The aim of this open-label , active-controlled , parallel group , phase 2 follow-up study was to assess the long-term immunogenicity of Epaxal Junior , the pediatric dose of an aluminum-free virosomal inactivated hepatitis A virus ( HAV ) vaccine , in children receiving routine childhood vaccines ( RCV ) . Methods : Healthy children ( 12–15 months old , ≥8 kg weight ) were r and omized ( 1:1:1 ) to group A : Epaxal Junior + RCV ( day 1 ) ; group B : Epaxal Junior ( day 1 ) + RCV ( day 29 ) and group C : Havrix 720 + RCV ( day 1 ) . All 3 groups received 2 doses of HAV vaccines 6 months apart . Children who completed the primary study were followed up from 18 months to 7.5 years post booster . Results : Of 291/327 r and omized children who had completed the primary study , 157 were followed for the 7.5-year analysis ( group A : 50 ; group B : 54 ; and group C : 53 ) . Of these , 152 children  had protective levels of anti-HAV antibodies [ ≥10 mIU/mL ; 98 % ( group A ) ; 96.3 % ( group B ) ; 96.2 % ( group C ) ] . Anti-HAV geometric mean concentrations were similar in groups A and B at all the time points ( 1.5- , 2.5- , 3.5- , 5.25- and 7.5-year time point ) but slightly lower in group C. Predictions of the median duration of persistence of seroprotective antibody levels , using the linear mixed model were similar in all groups : ( group A : 19.1 years , group B : 18.7 years , group C : 17.3 years ) . Conclusions : Immunization with Epaxal Junior administered with RCVs at 12 months elicited protective response beyond 7.5 years in almost all children . Assessing the kinetic of anti-HAV antibody titers decline over time , the moment to reach antibody concentrations below the accepted protective level may occur earlier than previously estimated The effect of passively transferred maternal antibody to hepatitis A virus ( anti‐HAV ) on the duration of seropositivity after hepatitis A vaccination during infancy and early childhood is unclear . We obtained levels of anti‐HAV at intervals through age 15‐16 years among three groups of Alaskan Native children who initiated a two‐dose inactivated hepatitis A vaccination series at ages 6 months ( group 1 ) , 12 months ( group 2 ) , and 15 months ( group 3 ) , each group r and omized according to maternal anti‐HAV status . Seropositivity ( anti‐HAV ≥20 mIU/mL ) 30 years after the second vaccine dose among the three groups was predicted using a r and om effects model . One hundred eighty‐three children participated in the study ; follow‐up did not differ significantly by vaccine group or maternal anti‐HAV status . Although the frequency of seropositivity among all participants through age 10 years was high ( 100 % among groups 2 and 3 and > 90 % among group 1 ) , there was a decrease thereafter through age 15‐16 years among group 1 children , who initiated vaccination at age 6 months ( 50%‐75 % ) , and among maternal anti‐HAV‐positive children in groups 2 and 3 ( 67%‐87 % ) , who initiated vaccination at ages 12 months and 15 months , respectively . Nonetheless , the model indicated that anti‐HAV seropositivity should persist for ≥30 years after vaccination in 64 % of all participants ; among those seropositive at age 15‐16 years , 84 % were predicted to remain so for ≥30 years . Conclusion : Most children vaccinated during early childhood available for sampling maintained seropositivity through age 15‐16 years ; however , seropositivity was less frequent among those starting vaccination at age 6 months and among maternal antibody‐positive participants who started vaccination at age 12 months or 15 months ; overall , our findings support current vaccine recommendations and continued follow‐up of this cohort . ( Hepatology 2016;63:703–711 Persistence of seropositivity conferred by hepatitis A vaccine administered to children < 2 years of age is unknown and passively transferred maternal antibodies to hepatitis A virus ( maternal anti‐HAV ) may lower the infant 's immune response to the vaccine . One hundred ninety‐seven infants and young children were r and omized into three groups to receive a two‐dose hepatitis A vaccine : group 1 at 6 and 12 months , group 2 at 12 and 18 months , and group 3 at 15 and 21 months of age . Within each group , infants were r and omized by maternal anti‐HAV status  . Anti‐HAV levels were measured at 1 and 6 months and at 3 , 5 , 7 , and 10 years after the second dose of hepatitis A vaccination . Children in all groups had evidence of seroprotection ( > 10 mIU/mL ) at 1 month after the second dose . At 10 years , all children retained seroprotective anti‐HAV levels except for only 7 % and 11 % of children in group 1 born to anti‐HAV – negative and anti‐HAV – positive mothers , respectively , and 4 % of group 3 children born to anti‐HAV – negative mothers . At 10 years , children born to anti‐HAV – negative mothers in group 3 had the highest geometric mean concentration ( GMC ) ( 97 mIU/mL ; 95 % confidence interval , 71‐133 mIU/mL ) and children born to anti‐HAV – positive mothers in group 1 had the lowest GMC ( 29 mIU/mL ; 95 % confidence interval , 20‐40 mIU/mL ) . Anti‐HAV levels through 10 years of age correlated with initial peak anti‐HAV levels ( tested at 1 month after the second dose ) . Conclusion : The seropositivity induced by hepatitis A vaccine given to children < 2 years of age persists for at least 10 years regardless of presence of maternal anti‐HAV . ( HEPATOLOGY 2012 OBJECTIVE To evaluate the safety , immunogenicity and fit dosage of Healive inactivated hepatitis A vaccine ( HAV ) in children . METHODS A total of 85 susceptible aged 4 - 10 years with HAV seronegative children , had been enrolled from two adjacent villages in a county . The volunteers were r and omized allocated into two groups and to receive a priming dose of 250 U/0.5 ml/dose or 500 U/1.0 ml/dose of Healive vaccine , produced by Sinovac Biotech Co , Ltd. A booster of the same dose was given at 12th month . Local and systemic side effects were examined and seroconversion rate as well as geometric mean titers of anti-HAV antibody were tested at 3-week , 12-month after the primary dose and at 1 month after the booster dose . RESULTS The vaccine was well tolerated in both groups . At 21 days after the primary dose , the seroconversion rates were 94.4 % , 100.0 % and geometric mean titers ( GMT ) were 195 mIU/ml and 370 mIU/ml in 250 U and 500 U groups respectively . At 12 months after the primary dose , the seroconversion rate of anti-HAV was 100.0 % , and GMT raised to 361 mIU/ml , 456 mIU/ml ( P > 0.05 ) respectively . One month after the booster dose , GMT raised to 14 893 mIU/ml , 21 696 mIU/ml . CONCLUSION GMT of the 0 , 12 month schedule was higher than other schedule after the booster vaccination . The Healive inactivated vaccine can be used for emergency vaccination . The Healive inactivated vaccine produced by Sinovac Company Ltd was safe and highly immunogenic . Two hundred and fifty U/dose was considered appropriate for children OBJECTIVE To evaluate the safety and efficacy of a new inactiv 
    Output:
    