Duration of hepatitis B immunity in low risk children receiving hepatitis B vaccinations from birth

The seroepidemiology of isolated core antibody against hepatitis B among Taiwanese adults - A large hospital-based study

BACKGROUND/PURPOSE

This study aims to investigate the prevalence of isolated core antibodies against hepatitis B (IAHBc) in different birth cohorts using a large medical record database.

METHODS

Hepatitis B viral serological test data were collected from a chart cloud database at a medical center in Taiwan between January 2006 and December 2018. The data collected included birth year, sex, hepatitis B viral markers (HBsAg, anti-HBs or anti-HBc), and hepatitis B vaccination records. Enrolled patients were grouped according to their birth year into three categories: ≤ 1986, 1987-1992, and ≥ 1993, which correspond to no neonatal hepatitis B immunization, plasma-derived HB vaccine (PDHBV), and recombinant hepatitis B vaccine (RHBV), respectively. Prevalence of hepatitis B viral seromarkers, including IAHBc, was calculated by sex, age groups, and birth cohorts. Those who underwent repeated hepatitis B serology tests were included for further analysis to follow up their serostatus.

RESULTS

A total of 117,335 adults with complete hepatitis B serologic data were analyzed. Among them, 6641 individuals (5.7 %) were found to have IAHBc. The prevalence of IAHBc was 11.4 %, 0.8 %, and 0.3 % among those born before 1986, between 1987 and 1992, and after 1992, respectively. Among the 690 subjects with repeated blood tests and complete hepatitis B serologic data, 551 cases (79.9 %) remained IAHBc. The other cases included resolved infection status (13.9 %), seronegativity for three HB seromarkers (3 %), and carrier of hepatitis B virus (2.3 %).

CONCLUSION

The management of individuals with IAHBc should be tailored to their age, vaccination status, and risk factors for occult hepatitis B viral infection.

Vaccine-preventable diseases: Immune response in a large population of healthcare students

BACKGROUND

Students in medicine and other health professions are exposed to numerous occupational hazards, primarily biological hazards, during their academic careers at university. The aim of the present study was to investigate the seroprevalence characteristics of anti-HBsAg, anti-Measles, anti-Mumps, anti-Rubella and anti-Varicella IgG antibodies in healthcare students of a large teaching hospital in Rome.

METHODS

To accomplish the study's aims, antibody serology data were gathered from students of Medicine and Surgery, Dentistry, and Health Professions at the Catholic University of the Sacred Heart (Rome Campus) during their first Health Surveillance visit, that took place from 2013 to 2023.

RESULTS

Our study sample included 2523 students, 44.4 % were protected against Hepatitis B, 87.3 % against measles, 85.5 % against mumps, 94.6 % rubella and 95.2 % against varicella. Differences in antibody coverage between age groups were statistically significant (p < 0.001), except for mumps. It found a lower probability of having seronegative anti-HBVs with an older date since the presumed primary vaccination.

CONCLUSION

In our sample, seropositivity rate against vaccine-preventable diseases, especially for Hepatitis B, was often inadequate to prevent possible biological risks connected with the activities carried out on the ward.

Single-Center Analysis of Essential Laboratory Testing in Patients with Newly Diagnosed Celiac Disease

OBJECTIVE

To analyze laboratory testing results from pediatric patients newly diagnosed with celiac disease to determine the usefulness of each test derived from recommended guidelines.

METHODS

Serological testing at the time of diagnosis from patients enrolled in our celiac disease registry from January 2018 through December 2021 was reviewed. The incidence of abnormal laboratory results, routinely obtained as per the recommendations of Snyder et al and our institution's Celiac Care Index, was assessed. Rates of abnormal laboratory values and estimated costs associated with these screening measures were analyzed.

RESULTS

Our data demonstrated abnormalities in all serological testing obtained at celiac diagnosis. Hemoglobin, alanine aminotransferase, ferritin, iron, and vitamin D screening were found to be abnormal with notable frequency. Only 7% of patients had an abnormal thyroid-stimulating hormone and <0.1% had an abnormal free T4. Nonresponse to hepatitis B vaccination was prominent, with 69% of patients considered nonimmune. Screening protocols as currently outlined in our Celiac Care Index resulted in an estimated cost of approximately $320 000 during our study.

CONCLUSIONS

Review of screening laboratory results at our center reveals that abnormal values for several recommended measures are uncommon. Thyroid screening was infrequently abnormal and the usefulness of screening for hepatitis B at diagnosis is uncertain. Similarly, our data suggest that iron deficiency screening may be condensed effectively into hemoglobin and ferritin testing, eliminating the need for initial iron studies. Decreasing baseline screening measures could safely decrease the burden of testing on patients and overall healthcare expenditures.

Immunogenicity of the pentavalent DTwP-HB-Hib vaccine (Shan-5) used in the Thai Expanded Program on Immunization compared to the hexavalent DTaP-HB-Hib-IPV and DTwP-HB-Hib (Quinvaxem) vaccines administered to infants at 2, 4, 6 months of age

BACKGROUND

The pentavalent DTwP-HB-Hib (Shan-5) vaccine was first introduced into the Thailand Expanded Program on Immunization (EPI) in 2019. The Shan-5 vaccine is administered to infants at 2, 4, and 6 months of age, after initial vaccination with monovalent hepatitis B (HepB) and Bacillus Calmette-Guérin (BCG) vaccines at birth. This study compared the immunogenicity of the HepB, diphtheria, tetanus, and Bordetella pertussis antigens incorporated in the EPI Shan-5 vaccine versus the optional pentavalent (DTwP-HB-Hib) Quinvaxem and hexavalent (DTaP-HB-Hib-IPV) Infanrix-hexa vaccine.

METHODS

Three-dose Shan-5-vaccinated children were prospectively enrolled at the Regional Health Promotion Centre 5, Ratchaburi province, Thailand, between May 2020 and May 2021. Blood sampling was performed at months 7 and 18. The levels of HepB surface antibody (anti-HBs), anti-diphtheria toxoid (DT) IgG, anti-tetanus toxoid (TT) IgG, and anti-pertussis toxin (PT) IgG were evaluated using commercially available enzyme-linked immunoassays.

RESULTS

Anti-HBs levels of ≥10 mIU/mL were achieved in 100 %, 99.2 %, and 99.2 % of infants in the Shan-5 EPI group, hexavalent group and Quinvaxem group one month after four dose immunization (at 0, 2, 4, 6 months of age), respectively. The geometric mean concentrations of the EPI Shan-5 and hexavalent groups were comparable but were higher than those of the Quinvaxem group. At one month after primary vaccination (month 7), infants in the Shan-5 EPI group had significantly higher levels of anti-DT IgG, anti-TT IgG, and anti-PT IgG than infants in the hexavalent and Quinvaxem groups.

CONCLUSIONS

The immunogenicity of the HepB surface antigen in the EPI Shan-5 vaccine was similar to that achieved by the hexavalent vaccine, but was higher than that achieved by the Quinvaxem vaccine. The Shan-5 vaccine is highly immunogenic and generates robust antibody responses after primary immunization.

Celiac Disease: Risk of Hepatitis B Infection

OBJECTIVE

The aim of our study was to assess the response to hepatitis B virus (HBV) vaccination and the risk of HBV infection in patients with celiac disease (CD).

PATIENTS AND METHODS

We performed a cross-sectional study using the National Health and Nutrition Examination Survey (NHANES) database (2009-2014) to assess the rate of HBV vaccination, immune response, and HBV infection risk in patients with and without CD. We also determined the rate of HBV infection via retrospective analysis of two cohorts: patients seen at Mayo Clinic (1998-2021), and a stable longitudinally observed cohort, the Rochester Epidemiology Project (REP; 2010-2020).

RESULTS

Based on the NHANES data, the rate of HBV infection in the United States was 0.33% (95% confidence interval 0.25-0.41). Of 93 patients with CD, 46 (49%) were vaccinated for HBV and of the remaining 19,422 without CD, 10,228 (53%) were vaccinated. Twenty-two (48%) vaccinated patients with CD had HBV immunity and 4405 (43.07%) vaccinated patients without CD had HBV immunity, which was not statistically different. In NHANES data, there were no cases of HBV infection in patients with CD. During the study period, 3568 patients with CD were seen at Mayo Clinic and 3918 patients with CD were identified using the REP database. Of those patients with CD, only four (0.11%) at Mayo Clinic and nine (0.23%) of the REP patients had HBV infection.

CONCLUSION

The rate of HBV vaccination and immunity was similar in individuals with and without CD. Predictably, no increased risk of HBV infection was detected in CD patients. These results do not support screening and revaccination practice for HBV immunity in patients with CD within the United States.

Hepatitis B in the Northern Territory: insights into the changing epidemiology of an ancient condition

Background

Aboriginal and Torres Strait Islander people are disproportionately affected by hepatitis B virus (HBV) infection. A proposed mismatch between standard vaccines and the HBV/C4 sub‐genotype prevalent in Aboriginal people in the Northern Territory (NT) may reduce vaccine effectiveness.

Aims

To determine HBV prevalence in the NT by Indigenous status and to explore patterns of immunity following implementation of universal vaccination, using a large longitudinal diagnostic dataset.

Methods

A retrospective analysis of all available HBV serology results in the NT from 1991 to 2011 was conducted, with HBV prevalence and vaccination status analysed according to adigenous status, age and sex using individuals' patterns of HBsAg, anti‐HBs and anti‐HBc serology over repeated tests.

Results

100 790 individuals were tested (33.4% Indigenous) between 1991 and 2011 (26.1% of the 2011 NT population), with a total of 211 802 tests performed. In 2011, the proportion of HBV positive individuals in the NT was 3.17% (5.22% in Indigenous populations) compared to previous 2011 estimates of 1.70% (3.70% in Indigenous populations). The vaccine failure rate was lower than expected with only one presumed vaccinated person subsequently developing HBsAg positivity (0.02%). Evidence of suboptimal vaccine efficacy by breakthrough anti‐HBc positivity in vaccinated individuals was demonstrated in 3.1% of the vaccinated cohort, of which 86.4% identified as Indigenous (HR 1.17). No difference in HBeAg positivity or seroconversion was observed between Indigenous and non‐Indigenous individuals living with CHB.

Conclusions

The burden of CHB in Indigenous people in the NT has previously been underestimated. A higher HBV prevalence in the NT than described in previous cross‐sectional studies was found, including a higher prevalence in Indigenous people. Evidence of suboptimal vaccine efficacy was demonstrated predominantly in Indigenous individuals.

High Risk of HBV Infection Among Vaccinated Polytransfused Children With Malignancy

AIM OF THE STUDY

The national Egyptian hepatitis B virus (HBV) vaccination program coverage of all infants started in 1992. The study aimed to assess immunity against HBV and occurrence of HBV breakthrough infections in vaccinated polytransfused children with malignancies.

PATIENTS AND METHODS

Eighty-nine polytransfused children with malignancies were recruited; 37 were on chemotherapy (male:female 20:17; mean age 7.7±4.0 y), and there were 52 naive patients (male:female 31:21; mean age 7.6±3.2 y). In addition, 162 age-matched and sex-matched healthy controls were recruited. Patients' sera were tested for quantitative anti-hepatitis B surface (HBs) (enzyme-linked immunoassays technique), hepatitis B surface antigen (HBsAg), total anti-hepatitis B core, and HBV-DNA (nested polymerase chain reaction for surface, core, and x-regions).

RESULTS

There was a significant lower percentage of having protective anti-HBs (10 to 100 IU/L) level among those receiving chemotherapy (13.5%) than those without (44.2%) and controls (32.1%). Twenty-one (67.7%) of those on chemotherapy were HBsAg positive compared with 10 (32.2%) of those without. Overall, 46 patients were HBV-DNA positive; 38 were c-region positive, 5 were s-region positive, 2 positive for the c-region and the s-region, and 1 tested positive for the c-region and the x-region. Of 46 patients, 20 were also positive for HBsAg (overt infection), while 26 had occult HBV infection (HBsAg-negative). Anti-HBs ≥10 IU/L co-existed among 45% of patients with overt infection and in 50% of those with occult infection. There was nonsignificant impact of receiving chemotherapy on the level of HBV-DNA.

CONCLUSIONS

Vaccinated children with malignancies, especially those under chemotherapy, are at a significant risk of HBV infection. The co-existence of anti-HBs with HBsAg and/or HBV-DNA may represent a possible residual transfusion-transmission risk with mutant HBV strains.

Hepatitis B vaccination in Indian children: Seroprotection and age-related change in antibody titres

Background

Childhood immunization against hepatitis B is one of the most effective strategies for reducing the global burden of chronic hepatitis B infection and its sequelae. There are limited data from India on both the anti-Hep B antibody titres in children after vaccination and the age-related decline in the titres. This study was planned to estimate the proportion of children in the age group of 1-10 years who develop protective levels of anti-hepatitis B antibodies after childhood vaccination and to examine the change in antibody titres with age in these children.

Methods

A hospital-based cross-sectional study was carried out in children admitted to the hospital for various ailments. Basic demographic data, vaccination history and HBsAg status of the mother were recorded. All the enrolled children were evaluated for HBsAg and anti hepatitis B surface antibody (anti-HBS) titres. Institutional ethical clearance was obtained, and informed consent from the parents of the children was taken before drawing samples.

Results

We found that 68.86% Confidence Interval ((CI): 59.8-76.8%) of the children showed protective antibody titres after vaccination, while 31.14% (CI: 23.1-40.2%) of the children had titres less than 10 IU/L. Although 100% of children in the age group from birth to three years had titres more than 10 IU/L, this percentage showed a decline across the age groups, and 60% of children aged 9-10 years had titres less than 10 IU/L.

Conclusion

Childhood vaccination against hepatitis B is effective in 68% children, and the antibody levels showed a steady decline with increasing age.

Hepatitis B Seroprevalence in the Pediatric and Adolescent Population of Florence (Italy): An Update 27 Years after the Implementation of Universal Vaccination

BACKGROUND

Hepatitis B still represents a health concern, although safe and effectivevaccines have been available since 1982. Italy introduced a program of universal vaccination againsthepatitis B in 1991. The aim of this study was to assess the immunity levels towards hepatitis B in asample of sera from the pediatric and adolescent population in the province of Florence, CentralItaly, twenty-seven years after the implementation of universal vaccination.

METHODS

A total of 165sera samples were collected from the resident population of Florence aged 1-18 years. The anti-HBsand anti-HBc enzyme-linked immunosorbent Assay (ELISA) tests were performed on all samples.The anamnestic and vaccination status data were also collected.

RESULTS

Seroprevalence of anti-HBswas approximately 60%, with children aged 1-5 years having the highest positivity rate (81.6%),and decreasing trends in the older age groups. The zero prevalence of anti-HBc shows that thedetected protective immunity is mainly due to vaccination, and natural infection was not reportedin the studied population.

CONCLUSIONS

The seroprevalence of anti-HBs and the lack of anti-HBc inthis study highlights that immunity levels have been derived mainly from immunization. Thisconfirms how vaccination dramatically reduced circulation of the hepatitis B virus in Italy in thepediatric and adolescent population twenty-seven years after implementation of the mandatoryuniversal program.

Blood-borne viral infections in pediatric hemodialysis

Hemodialysis patients are at increased risk for development of blood-borne viral infections. Human immunodeficiency virus (HIV), a once fatal infection, has become treatable, but continues to be associated with increased mortality. Hepatitis B and C viral infections can lead to acute and chronic hepatitis, cirrhosis, or hepatocellular carcinoma. Young children and immunocompromised patients are more likely to develop chronic disease leading to increased morbidity and mortality, as compared to the healthy population. The hemodialysis population is at increased risk of blood-borne viral infections as compared to the general population due to multiple factors. Here we review risk factors of blood-borne viral infections, strategies for prevention, and approach to therapy in the pediatric hemodialysis population.

Persistence of Immunity for Hepatitis B Virus among Heathcare Workers and Italian Medical Students 20 Years after Vaccination

Background: Immunization of healthcare workers (HCWs) and medical students for the hepatitis B virus (HBV) is a crucial part of the hospital infection control programs. The aim of our study was to evaluate the persistence of anti-HBV specific antibodies in HCWs vaccinated during infancy or adolescence. Methods: Medical records of 734 consecutive subjects born after 1980 (481 females, 65.5% and 253 males, 34.5%) who underwent serological testing for anti-hepatitis B surface antibodies (anti-HBs) were evaluated. Results: A non-protective titer (<10 mUI) was found in 88/734 (12.0%) subjects; 84 (47.8%) of them received a booster dose of anti-hepatitis B vaccine and the anti-HBs titer of 58 subjects was measured 1 month after administration. A protective titer (anti-HBs >10 mIU/mL) was observed in almost 90% of subjects receiving the booster dose. Conclusions: A substantial percentage of HCWs had a non-protective anti-HBs titer at the time of the first employment, especially those vaccinated at birth age. However, the response to the booster dose showed that in these subjects, an anti-HBs titer <10 mIU/mL was due to the physiological decline of antibodies over the years. Therefore, primary immunization in childhood is highly effective and provides lasting immunity against HBV infection.

Persistence of hepatitis B surface antibody and immune memory to hepatitis B vaccine among medical college students in Madinah

BACKGROUND

Globally, about 300 million people are infected with hepatitis B virus (HBV). Among the effective approaches to fight HBV infection is immunization. In 1989, an obligatory hepatitis B vaccine program was launched in Saudi Arabia.

OBJECTIVE

Assess hepatitis B surface antibody (anti-HBs) levels among the medical students before and after receiving booster doses of HBV vaccine.

DESIGN

Cross-sectional.

SETTING

Taibah University.

SUBJECTS AND METHODS

Students born between 1993 and 1995 were recruited in this study from the Occupational Health Clinic. Students were screened for anti-HBs levels using chemiluminescent microparticle immunoassay (CMIA) before and after booster HBV vaccine doses.

MAIN OUTCOME MEASURES

Anti-HBs levels before and after booster doses.

SAMPLE SIZE

335.

RESULTS

About half of participants (n=164, 49%) had protective anti-HBs levels ( greater than or equal 10 mIU/mL) to the original primary series of HBV vaccine and received no booster doses. The reimaining 171 (51%) participants were at risk of HBV infection since their anti-HBs levels were less than 10 mIU/mL, despite having received the original primary HBV vaccine. The levels of anti-HBs were higher in female than in male students (P less than .001). In addition, female students showed a stronger humoral immune response to the booster vaccine than male students (P less than .001). When participants were given the three boosters, most participants (98.3%) showed anti-HBs levels of greater than or equal 10 mIU/mL. The results also showed a strong correlation between pre-booster and post-booster anti-HBs levels in the greater than or equal 10 mIU/mL group (r2= 0.52, P less than .001) but not in less than 10 mIU/mL group (r2= 0.003, P=.53).

CONCLUSION

A considerable portion of the participants (about 51%) were at risk of HBV infection since their anti-HBs levels were less than 10 mIU/mL. Booster doses significantly trigger memory immune response and this ensured their protection against the virus. Pre-booster anti-HBs level are a good predictive of post-booster anti-HBs levels in greater than or equal 10 mIU/mL group.

LIMITATIONS

The sample size was small. Shortage of collaborators.

CONFLICT OF INTEREST

None.

Prevalence of serum markers of infection and naturally acquired immunity to hepatitis B virus in transfused children treated at a children's hospital in Salvador, Bahia: A cross-sectional study

The artificially acquired humoral immunity against hepatitis B virus (HBV) apparently may decline over the years. This study aimed to investigate the prevalence of naturally occurring serological markers of infection and active immunity to HBV in severely ill children and adolescents treated at the Martagão Gesteira Pediatric Hospital who received blood transfusions. The serum samples of 353 children who received poly-transfusions between August 2016 and March 2017 were tested for HBV surface antigen (HBsAg) markers, anti-HBc antibodies (IgG and IgM isotypes), and IgG anti-HBs. None of the children presented an outcome compatible with HBV infection. Three patients were seroreactive to markers of past infection, tested positive for anti-HBc IgG and negative for anti-HBc IgM, and were seropositive for anti-HBs, with antibody titers of >150.00 mIU/mL. Only 52.4% of the patients in the study were protected against HBV, with anti-HBs antibody titers of >10 mIU/mL. Children aged 5 years had lower titers of anti-HBs. The results indicated that the older children were more likely to be unprotected from HBV; this suggests the need to evaluate the vaccine response in children, especially those who received blood transfusions.

From infancy and beyond… ensuring a lifetime of hepatitis B virus (HBV) vaccine-induced immunity

Despite the long-term efficacy and immune persistence observed following HBV vaccination of infants, the need for a booster dose following infant immunization continues to be deliberated. Evidence from HBV booster dose response studies and long-term immunization program reviews are the basis for the recommendation that a vaccine booster is not necessary. However, further studies continue to emerge and highlight the need for standardization among observational studies in order to appropriately compare outcomes. There is an assumption that neonatal and infant (within 12 months of age) vaccine immune responses are equivalent; however, evidence exists for distinct vaccine responses within the first year of life. HBV vaccine programs have evolved over time, particularly regarding the type and dosage of vaccine used. Several universal neonatal immunization programs initially incorporated a 2.5 μg dosage (Recombivax-HB, Merck). This dosage has been shown in multiple long-term studies and meta-analyses to be associated with a lower primary response, decreased antibody persistence over time, and a reduced booster response 10 to 20 years following immunization. Ongoing surveillance of this and other HBV neonatally-vaccinated populations, particularly in low endemic regions, is necessary to understand the impact on long-term protection in order to ensure lifelong protection against hepatitis B infection.

Early and long term anamnestic response to HBV booster dose among fully vaccinated Egyptian children during infancy

OBJECTIVE

To evaluate early and long term anamnestic response to a booster dose of HBV vaccine among non-seroprotected children.

SUBJECTS AND METHOD

A national community based project was carried out on 3600 children aged 9 months to 16 years, fully vaccinated during infancy. They were recruited from 6 governorates representing Egypt. It revealed that 1535 children (42.8%) had non sero-protective anti-HBs (<10 IU/L) and were HBsAg or anti-HBc negative. A challenging dose of 10 μg of mono-valent Euvax HBV vaccine was given to 1121/1535 children. Quantitative assessment of anti-HBs was performed to detect early (2-4 weeks) and long term (one year) anamnestic responses.

RESULTS

Early anamnestic response developed among 967/1070 children (90.3%).Children having detectable anti-HBs (1-9 IU/L) significantly developed early anamnestic response (90%) compared to 85% with undetectable anti-HBs (<1 IU/L), P < 0.001. Multiple logistic analysis revealed that undetectable anti-HBs, living in rural residence and children aged 15-16 years were the most significant predicting risk factors for the absence of early anamnestic response (<10 IU/L), with AOR 2.7, 2.7 & 4.7 respectively. After one year, long term anamnestic response was absent among 15% of children who previously showed early response. Poor early anamnestic response and undetectable pre-booster anti-HBs were the significant predicting risk factors for absent long term anamnestic response, with AOR 18.7 & 2.7 respectively.

CONCLUSION

Immunological memory for HBV vaccine outlasts the presence of anti- HBs and HBV vaccination program provides effective long term protection even in children showing waning or undetectable concentrations of anti-HBs. This signifies no need for a booster dose especially to healthy children.

Incidence of Low Seroimmunity to Hepatitis B Virus in Children With Inflammatory Bowel Disease

OBJECTIVES

Patients with inflammatory bowel disease (IBD) often receive immunosuppressive therapy, which may make them vulnerable to infections such as hepatitis B. We hypothesized that hepatitis B virus titers are low in the vaccinated pediatric population with IBD. The aims of our study were to identify the incidence of lower titers of hepatitis B surface antibody (HBsAb) and determine which patient factors may be associated with lower HBsAb titers.

METHODS

Patients with diagnosis of IBD, ages 5 to 18 years, were prospectively enrolled. Patients were confirmed to have had a full series of hepatitis B vaccination. Quantitative serum HBsAb titers were measured and logistic regression analysis with independent variables of age, sex, race, disease phenotype, surgery, medications and a dependent variable of adequate HBsAb titers (> 10 mIU/mL) was performed.

RESULTS

Of the 116 patients enrolled, 57 were boys and 59 were girls. 75 patients had a diagnosis of Crohn disease; 32 had a diagnosis of ulcerative colitis; and 9 patients had been diagnosed as having indeterminate colitis. At the time of the study, 15 patients were taking corticosteroid, 66 on an immunomodulator, and 53 on a biologic. Sixty percent of patients in the 5- to 10-year age group had protective titers versus 22% to 27% in the older groups, P = 0.04. Only 28% of the 116 patients had HBsAb titers of >10m IU/mL. Twenty percent of the patients taking corticosteroids, 27% taking immunomodulators, and 24% taking biologics were found to be seroimmune.

CONCLUSIONS

Nearly two-thirds of pediatric patients with IBD have low titers against hepatitis B virus. Titers were highest in the younger patients. No patient-specific variable, such as the use of immunosuppressants, appeared to influence these low titers.

Persistence of Hepatitis B Immunity Following 3-dose Infant Primary Series in HIV-infected Thai Adolescents and Immunologic Response to Revaccination

BACKGROUND

HIV infection may alter immunologic response and the establishment of immune memory to infant hepatitis B virus (HBV) vaccination. This study aimed to determine the need to revaccinate perinatally HIV-infected Thai adolescents.

METHODS

Cross-sectional serologic tests for HBV, including hepatitis B surface antigen, anti-hepatitis B surface antibody (anti-HBs) and anti-hepatitis B core antibody (anti-HBc), were performed in perinatally HIV-infected adolescents. Adolescents having anti-HBs <100 mIU/mL with negative anti-HBc and immune reconstitution from highly active antiretroviral therapy (HAART) were revaccinated using regular (10 μg) 3-dose schedule given intramuscularly at 0-, 2- and 6-month intervals.

RESULTS

Of 193 adolescents who received 3-dose infant HBV vaccination, 6 were receiving HAART during vaccination, median (interquartile range) current age 14.5 (11.7-16.2) years, 7 (3.6%) had positive anti-HBc (indicating breakthrough infection), of which 4 (2%) had positive hepatitis B surface antigen (indicating chronic infection). Twenty-two (11.4%) adolescents had protective anti-HBs concentration >10 mIU/mL. Of 164 revaccinated adolescents, 142 (86.6%) had HIV viral load <40 copies/mL. Anti-HBs seroconversion rates >10 mIU/mL were 58.0% (94/162) after the first dose and 97.5% (158/162) after the third dose of revaccination. Forty-five (28%) subjects responded to the first dose with anti-HBs antibody ≥100 mIU/mL had a shorter median duration with CD4 count <15% than their counterparts (6.2 vs. 11.1 months; P = 0.049).

CONCLUSIONS

Only half of perinatally HIV-infected adolescents were able to elicit anti-HBs response with a single-dose HBV vaccine. Revaccination with 3-dose schedule is required in perinatally HIV-infected adolescents who did not initiate HAART at the time of infant vaccination.

Epidemiology of hepatitis B and the role of vaccination

Hepatitis B virus (HBV) is a major cause of morbidity and mortality with a disproportionate impact on Asia and Africa. Current guidelines recommend screening at-risk populations for chronic HBV infection so that diagnosed individuals can be linked to appropriate hepatitis care. The vast majority of infected individuals are undiagnosed and untreated, and are at risk of developing cirrhosis, liver failure, and hepatocellular carcinoma. In individuals who are not yet infected, the HBV vaccine is safe and highly effective at preventing disease transmission. Countries with successful vaccination programs have been able to dramatically reduce their HBV prevalence. A concerted effort to screen, treat, and vaccinate at-risk individuals has the potential to eliminate HBV as a public health threat by 2030.

Immune responses to hepatitis B immunization 10-18 years after primary vaccination: a population-based cohort study

We evaluated the immune response to neonatal HBV immunization in children of infected parents 10-18 years after primary vaccination. Healthy individuals immunized with an infantile course of three doses of HBV vaccine were tested for persistence of anti-HB surface antibody (HBsAb). Those with an HBsAb level of <10 IU/mL received a booster dose of the vaccine with subsequent doses to those without protective titres. HBsAb concentrations were determined 4 weeks after each dose of the booster vaccine. The data were analysed separately for three age groups: 10-11, 12-14 and 15-18 years old. A total of 541 healthy individuals were studied. The highest seroprotection rate of 48% was observed in the youngest vaccinees (10-11 years old). This declined to 26.5% in the oldest (15-18 years old) group (P = 0.008). The youngest vaccinees showed the highest rate of anamnestic immune responses (96%). However, 25% of oldest individuals failed to mount an anamnestic immune response in challenge with a booster dose of the vaccine (P = 0.005), suggesting waning immunity with increasing age. Age (OR: 0.80; P = 0.01) and prebooster HBsAb levels (OR: 0.37; P = 0.01) identified responders to first booster doses of the vaccine by logistic regression analysis. The majority of high-risk vaccinees showed anamnestic immune response 10-11 years after primary immunization. However, we found a significant proportion (25%) of older individuals with no anamnetic response, which suggests a waning of immune memory. Detailed long-term follow-up studies are necessary to determine the risk of natural infection among these individuals before a booster schedule can be recommended.

Response to anti-HBV vaccine and 10-year follow-up of antibody levels in healthcare workers

BACKGROUND

Despite improvements in public health and antiviral treatments, vaccination is still the most effective means of prevention of hepatitis B virus (HBV) infection. However, little is known about the duration of protection given by the anti-HBV vaccine. Healthcare workers represent a category at risk not only of contracting infection but also of being a source of contagion to patients.

OBJECTIVES

To assess individual responses to the anti-HBV vaccine and duration of protection 10 years after its administration in a cohort of healthcare workers employed by the University Hospital 'G. Martino' in Messina, Italy.

METHODS

One hundred and seventy medical staff who had been vaccinated following an incident carrying risk of HBV infection were included in this study. The group was followed over a 10-year period, and HBV antibody levels were assessed using an automated microparticle enzyme immunoassay.

RESULTS

Protective antibody levels (≥10 mIU/ml) were found in 65% of subjects who had completed the full vaccine schedule (three doses) and in 35% of subjects who had only received one or two doses of anti-HBV vaccine. Moreover, 10 years after vaccination, HBV antibody levels were inversely related to age at vaccination (P < 0.001). No differences were found between males and females.

CONCLUSIONS

This study, in line with the literature, shows the importance of completing the full vaccine schedule (three doses). Moreover, in order to have an effective and durable antibody response and avoid the risk of contracting HBV after an injury at work, it is important to recommend anti-HBV vaccination at a young age, ideally during childhood in accordance with the national vaccination policy.

Impact of Universal Hepatitis B Vaccination on Prevalence, Infection-Associated Morbidity and Mortality, and Circulation of Immune Escape Variants in Russia

Vaccination of newborns against hepatitis B (HB) was introduced in Russia in 1998. Since then the incidence of acute HB has rapidly declined. However, prevalence of chronic HB remains stable. The aim of this study was to estimate the effect of vaccination on HBV-associated morbidity, and to assess the prevalence of HBV immune escape variants after 10 years of vaccination.

A Longitudinal Hepatitis B Vaccine Cohort Demonstrates Long-lasting Hepatitis B Virus (HBV) Cellular Immunity Despite Loss of Antibody Against HBV Surface Antigen

BACKGROUND

Long-lasting protection resulting from hepatitis B vaccine, despite loss of antibody against hepatitis B virus (HBV) surface antigen (anti-HBs), is undetermined.

METHODS

We recruited persons from a cohort vaccinated with plasma-derived hepatitis B vaccine in 1981 who have been followed periodically since. We performed serological testing for anti-HBs and microRNA-155 and assessed HBV-specific T-cell responses by enzyme-linked immunospot and cytometric bead array. Study subgroups were defined 32 years after vaccination as having an anti-HBs level of either ≥10 mIU/mL (group 1; n = 13) or <10 mIU/mL (group 2; n = 31).

RESULTS

All 44 participants, regardless of anti-HBs level, tested positive for tumor necrosis factor α, interleukin 10, or interleukin 6 production by HBV surface antigen-specific T cells. The frequency of natural killer T cells correlated with the level of anti-HBs (P = .008). The proportion of participants who demonstrated T-cell responses to HBV core antigen varied among the cytokines measured, suggesting some natural exposure to HBV in the study group. No participant had evidence of breakthrough HBV infection.

CONCLUSIONS

Evidence of long-lasting cellular immunity, regardless of anti-HBs level, suggests that protection afforded by primary immunization with plasma-derived hepatitis B vaccine during childhood and adulthood lasts at least 32 years.

The effect of simple imputation on inferences about population means when data are missing in biomedical research due to detection limits

The sample geometric mean has been widely used in biomedical and psychosocial research to estimate and compare population geometric means. However, due to the detection limit of measurement instruments, the actual value of the measurement is not always observable. A common practice to deal with this problem is to replace missing values by small positive constants and make inferences based on the imputed data. However, no work has been carried out to study the effect of this naïve imputation method on inference. In this report, we show that this simple imputation method may dramatically change the reported outcomes of a study and, thus, make the results uninterpretable, even if the detection limit is very small.

Serologic control against hepatitis B virus among dental students of the University of Granada, Spain

Background

To evaluate the immunological situation against hepatitis B virus (HBV) of a cohort of dentistry students, to analyze the behavior of the levels of hepatitis B surface antigen (anti-HBs) after the administration of one or three vaccine doses, and to determine the influence of age and sex on the immune response.

Material and Methods

This retrospective cohort study included students attending the School of Dentistry of the institution where the study was performed from 2005 to 2012 who had completed the public health vaccination calendar for HBV at the age of 12-13. Data on age, sex, basal anti-HBs levels, post-vaccination anti-HBs results and final anti-HBs levels were collected. Comparisons of the basal and final levels, as well as associations regarding age and sex, were performed by means of the Student t and Chi-square tests.

Results

Of the 359 students, 97 (27.02%) had basal antibody concentrations <10 mIU/ml, whereas in 262 the levels of anti-HBs were ≥10 mIU/ml (72.98%). Of the 288 participating students who completed the School´s protocol for immunization, 287 (99.65%) attained a level of protection ≥10 mIU/ml. Globally, there were statistically significant differences between the basal antibody levels and those achieved after administration of the vaccine and booster, but no association with age or sex was observed.

Conclusions

About 70% of dental students vaccinated as preadolescents had serologic evidence of protection against HBV. Administering a booster is associated with the presence of an excellent immune memory. There is clearly a need to reinforce control of the antibody levels in groups at risk, such as Dentistry students.

Key words:Dental students, hepatitis B virus, serologic control.

Immunogenicity of Recombinant Hepatitis B Vaccine Among Routinely Vaccinated Healthy and Chronically Ill Children in Assiut, Upper Egypt

BACKGROUND

Egypt is considered a region of the intermediate prevalence of hepatitis B virus (HBV) infection (4.5%). Seroprotection is assured when hepatitis B surface antibody (HBsAb) levels are ≥ 10 mIU/mL. Our study aimed to evaluate and compare the long-term immunogenicity and efficacy of the recombinant hepatitis B (HB) vaccine.

METHODS

A cross-sectional study was done for children aged from 9 months to 15 years, receiving health care at Assiut University Children's Hospital, Assiut, Egypt in 3 months. HBsAb was quantitatively determined by enzyme-linked immune sorbent assay (ELISA).

RESULTS

Seroprotection in infants less than 1 year was 89.7% with 55.2% having titer > 100 mIU/mL and this percent dropped to 64.4% after the first year of age with only 29% having titer > 100 mIU/mL. The overall protection percentage was 32.5% (> 100 mIU/mL), 34.7% of children showed levels between 10 and 100 mIU/mL, while 32.8% were less than 10 mIU/mL. Patients with diabetes mellitus were found to have the lowest seroprotective levels (83.3% were not protected). Non-protective levels were also detected in patients with malnutrition (55.6%), congenital heart diseases (43.2%) and chronic liver diseases (57.1%).

CONCLUSION

Our study shows failure to achieve satisfactory seroprotective levels for hepatitis B vaccine in both healthy and diseased children who adopted vaccination schedule in Upper Egypt. Booster dose in the second year of life is recommended for all children, particularly for those with diabetes millets, congenital heart disease and malnutrition.

The duration of hepatitis B vaccine immunity in pediatric dialysis patients

BACKGROUND

Dialysis patients are at risk for hepatitis B infection, a serious but preventable disease. Long-term hepatitis B protection has not been defined in pediatric patients with chronic kidney disease stage 5 on dialysis (CKD 5D) who were vaccinated as infants or children.

METHODS

Annual hepatitis B antibody surveillance data were collected retrospectively on a cohort of pediatric CKD 5D patients (n = 202) at a single institution and analyzed by survival analysis to assess hepatitis B immunity duration.

RESULTS

Median duration of immunity by Kaplan-Meier analysis since primary vaccination was 106.3 [95 % confidence interval (CI) 93.9, 124.4] months. After the initiation of dialysis, the median duration of hepatitis B immunity was 37.1 (95 % CI 24.2, 72.3) months. Multivariate adjusted analysis showed that there was a significant difference in the duration of hepatitis immunity based on the timing of hepatitis B vaccination (p < 0.001). Patients immunized after starting dialysis had a hazard ratio of 6.13 (95 % CI 2.87, 13.08) for hepatitis B immunity loss compared to patients immunized as infants (p < 0.001).

CONCLUSIONS

After dialysis initiation, protective hepatitis B antibody levels wane rapidly, with a shortened duration of immunity. In our cohort of pediatric patients with CKD 5D, this decline was more pronounced in children who were immunized after starting dialysis than in those who received hepatitis B immunizations during childhood. Both groups of patients should be monitored with serial antibody titers.

Alternative dosage schedules with HPV virus-like particle vaccines

HPV vaccines can prevent multiple cancers in women and men. Difficulties in the cost and completion of the three-dose vaccine series have led to considerations of alternative dose schedules. In clinical trials, three doses given within a 12-month period versus the standard 6-month period yielded comparable results, and immunogenicity appears comparable with two doses in adolescent females compared to the three-dose series in adult females. While the data are generally supportive of moving to a two-dose vaccine schedule among young female adolescents, the adoption of a two-dose vaccine schedule still poses a potential risk to the strength and longevity of the immune response. Public health authorities implementing a two-dose vaccine schedule should devise risk management strategies to minimize the potential impact on cancer prevention.

Duration of protection after infant hepatitis B vaccination series

BACKGROUND

Little is known about duration of protection after the infant primary series of hepatitis B (HB) vaccine in settings of low HB endemicity. This study sought to determine the proportion of adolescents immunized as infants who had protective titers of antibody to hepatitis B surface antigen (anti-HBs) before and after a challenge dose of vaccine.

METHODS

US-born 16- through 19-year-olds who received a recombinant HB vaccine 3-dose series initiated within 7 days of birth (group 1) or at ≥4 weeks of age (group 2) and completed by 12 months of age were enrolled. Participants had serologic testing before and 2 weeks after randomization to receive a challenge dose of 10 µg or 20 µg of Engerix-B. Baseline and postchallenge levels of anti-HBs were compared by group, challenge dosage, and demographic and behavioral characteristics.

RESULTS

At baseline, 24% had protective anti-HBs levels of ≥10 IU/mL; 92% achieved protective levels after challenge dose. Although group 1 had a lower proportion of seroprotection at baseline, group and challenge dosage were not associated with postchallenge proportion of seroprotection. Being in group 2, higher test dosage, higher baseline geometric mean titer, and nonwhite race were associated with significantly higher geometric mean titer after challenge dose.

CONCLUSIONS

More than 90% of study participants immunized against HB as infants exhibited a seroprotective response to a challenge dose of vaccine. Duration of protection from the primary infant HB vaccine series extended through the adolescent years in the setting of low HB endemicity.

Chronic hepatitis B in children and adolescents: epidemiology and management

Hepatitis B virus (HBV) infection is a worldwide health problem, which can cause acute liver failure, acute hepatitis, chronic hepatitis, liver cirrhosis, and liver cancer. It is most prevalent in Asia, Africa, Southern Europe, and Latin America. Approximately 2 billion people in the world have been infected by HBV, with more than 350 million as chronic carriers. Implementation of the HBV vaccine led to a significant reduction in viral transmission in many areas of the world; however, it remains highly endemic in many developing countries. The main source of infection in childhood is via perinatal transmission or horizontal transmission during preschool years. The majority of children with chronic hepatitis B (CHB) infection are asymptomatic; however, they may develop progressive disease and are at increased risk of advanced liver disease or liver cancer before their third decade. All children with chronic HBV infection should be regularly monitored for disease progression. The goal of therapy for children with CHB is to arrest disease progression and reduce the risk of developing cirrhosis and cancer. The available medications have a low success rate because of immunotolerance in the child and the development of viral resistance to standard therapy. Therefore, case selection and determination of the best time to commence treatment are essential to increase treatment efficacy and reduce the risk of viral resistance.

Long-term persistence of immunity after vaccination of pre-adolescents with low doses of a recombinant hepatitis B vaccine

BACKGROUND AND AIMS

Recent studies have shown no detectable antibodies and no response to a challenge dose of vaccine 10-20 y after receiving low doses (2.5-5 µg) of recombinant hepatitis B vaccine during first months of life. Little information is available on long-term persistence of immunity after vaccinating pre-adolescents with low doses of hepatitis B vaccine.

RESULTS

The results of 560 subjects were included in this analysis. All subjects had a seroprotective antibody titer (≥10 IU/L) one month post-primary vaccination; 5, 10 and 15 y post-vaccination 95%, 95% and 87% had detectable antibodies, and 82%, 86%, and 68% had a seroprotective antibody titer; GMTs were 73 IU/L, 89 IU/L, and 28 IU/L, respectively. More than 99.4% of subjects had an anamnestic response to a challenge dose of vaccine given 5, 10, or 15 y post-vaccination. Five and ten years post-booster dose 97% and 95% of subjects still have a seroprotective anti-HBs titer with GMTs 16-18-fold higher when compared with those observed 5-10 y post-primary vaccination.

MATERIALS AND METHODS

This randomized trial was initiated in 1996 with the main objective to assess the persistence of antibodies and immune memory 5, 10 and 15 y after vaccinating 8-10 y-old children with three doses of Recombivax 2.5 µg, as well as the short and long-term effect of a booster dose given at different intervals.

CONCLUSIONS

Virtually all children vaccinated at the age of 8-10 y with low doses of hepatitis B vaccine still have an excellent immune memory up to age of 25 y. The results of this study do not support the use of booster doses.

Determinants of Long-term protection after hepatitis B vaccination in infancy: a meta-analysis

BACKGROUND

The duration of protection after hepatitis B vaccination in early infancy is unclear and may be related to vaccination schedule, dosage, vaccine type and population characteristics. Factors potentially influencing waning immunity were assessed.

METHODS

A systematic review was performed. The main outcomes were prevalence of anti-hepatits B antibodies ≥ 10 mIU/mL after primary or booster vaccination. Factors potentially influencing protection were assessed in an adjusted random-effects meta-analysis model by age for both outcomes. Results of both meta-analyses were combined in a prognostic model.

RESULTS

Forty-six studies reporting on the anti-hepatits B antibodies ≥ 10 mIU/mL 5 to 20 years after primary immunization and 29 on booster response were identified. The adjusted meta-analyses identified maternal carrier status (odds ratio [OR]: 2.37 [1.11; 5.08]), lower vaccine dosage than presently recommended (OR: 0.14 [0.06; 0.30]) and gap time between last and preceding dose of the primary vaccine series (OR: 0.44 [0.22; 0.86]) as determinants for persistence of anti-hepatits B antibodies ≥ 10. A lower vaccine dosage was also associated with failure to respond to booster (OR: 0.20 [0.10; 0.38]). The prognostic model predicted long-term protection of 90% [77%; 100%] at the age of 17 years for offspring of noncarrier mothers vaccinated with a presently recommended dose and vaccination schedule.

CONCLUSIONS

Based on meta-analyses, predictors of waning immunity after hepatitis B vaccination in infancy could be identified. A prognostic model for long-term protection after hepatitis B vaccination in infancy was developed.

Immune memory and immune response in children from Bulgaria 5-15 years after primary hepatitis B vaccination

BACKGROUND

Bulgaria adopted the World Health Organization recommendation of routine universal infant vaccination against hepatitis B in 1991. Nevertheless, only a few studies evaluated the protection after the vaccination against hepatitis B, especially in children. The objective of this study was to investigate the duration of protection against hepatitis B in children aged 5-15 years after primary immunization, by measuring the immune and anamnestic immune response and possible breakthrough infections.

METHODS

A total of 141 children (aged 5-17 years) were recruited randomly and divided into 3 groups, approximately 5 years (group 1), 10 years (group 2) and 15 years (group 3) after primary immunization with a recombinant hepatitis B vaccine; they were tested for hepatitis B markers: hepatitis B surface antigen anti-hepatitis core antibody and antibodies to hepatitis B surface antigen (anti-HB). A booster dose of vaccine was administered to 23 children with titers of anti-HBs antibodies below the threshold considered to be protective (<10 mIU/mL). Anti-HBs concentrations and geometric mean concentration (GMC) were determined before and 21-28 days after the booster vaccination.

RESULTS

Protective anti-HBs antibodies were detected in 95 of 141 (67.4 %) tested children, with a GMC of 63.57 mIU/mL. The seroprotection rate and GMC by groups was respectively: 84.6% and GMC of 76.05 mIU/mL in group 1; 55.8% and GMC of 58.1 mIU/mL in group 2; and 61.1% and GMC of 50.33 mIU/mL in group 3. Hepatitis B surface antigen and anti-hepatitis core antibody were found in 1 of the 141 subjects (0.7%). Of the remaining 140 children, 95 had anti-HBs ≥10 mIU/mL, and anti-hepatitis core antibodies were not detected. A booster dose of hepatitis B vaccine was administered to 23 of 45 (51%) children with anti-HBs <10 mIU/mL. Anamnestic immune response was shown in 100% of the children: the GMC was 337.38 mIU/mL and protective antibodies ranged between 15 and 955 mIU/mL.

CONCLUSION

The study demonstrates the presence of immune memory and protection 5-15 years after the initial course of newborn immunization with recombinant vaccines against hepatitis B.

Persistence of protection of hepatitis B vaccine and response to booster immunization in 2- to 12-year-old children

Neonatal vaccination against hepatitis B virus (HBV) infection was launched in 1998 in Turkey. The aim was to evaluate the persistence of seroprotection after HBV vaccination in order to determine the necessity of a single booster dose in 2- to 12-year-old children. This study was conducted retrospectively using hospital records of the children aged 2-12 years old who attended the pediatric outpatient clinics of Diskapi Training and Research Hospital, Ankara, Turkey between January 2010 and June 2011. Children who had received three doses of HBV vaccination in their infancy were included. A total of 530 children enrolled into the study, and 352 (66.4 %) of them had protective antibody to hepatitis surface antigens (anti-HBs) titer greater than 10 mIU/ml. The proportions of children with low, intermediate, and high anti-HB titers are different for those under 3 years of age. The majority were in the intermediate category. Those aged 4-10 years and 11 or older represented two-thirds of the children with high titers (p = 0.000). None of the children had chronic HBV infection. Unprotected children responded well after receiving the booster dose. The mean anti-HB concentration after the booster dose was more than 200 times higher than the mean antibody concentration before (p < 0.001).

CONCLUSION

Our data suggest that HBV vaccination may confer long-term immunity. Use of routine booster doses of vaccine at these ages does not appear necessary to maintain long-term protection in successfully vaccinated immunocompetent children in the region.

Antibody persistence and the effect of a booster dose given 5, 10 or 15 years after vaccinating preadolescents with a recombinant hepatitis B vaccine

The persistence of antibody obtained post-vaccination of preadolescents with three doses of Engerix-B and the effect of a booster administered 5, 10 or 15 years later were monitored in 663 vaccinees. Five, 10 and 15 years post-vaccination >94% of subjects had detectable antibodies and 88.2%, 86.4% and 76.7% had a titre ≥10 IU/L; GMTs were 269 IU/L, 169 IU/L and 51 IU/L, respectively; 99.1-100% vaccinees reached a titre ≥10 IU/l post-booster. GMTs were 118012 IU/L, 32477 IU/L, and 13946 IU/L when the booster was administered 5, 10 or 15 years post-vaccination, respectively. We conclude that vaccination induces immunity in the great majority of vaccinees for at least 15 years. The response to a booster dose suggests persistence of immune memory in almost all vaccinees. Although a booster dose increases substantially anti-HBs titres, the clinical relevance of such an increase remains unknown. These results do not support the need of a booster for at least 15 years when vaccinating preadolescents with Engerix-B.

Significance and anamnestic response in isolated hepatitis B core antibody-positive individuals 18 years after neonatal hepatitis B virus vaccination in Taiwan

AIM

To investigate the significance of isolated hepatitis B core antibody (anti-HBc) and to analyze the response to hepatitis B virus (HBV) booster vaccination in young adults with isolated anti-HBc who had been fully vaccinated with HBV vaccine as infants.

MATERIALS AND METHODS

We screened 1734 new university entrants who had been fully vaccinated against HBV in infancy for the presence of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and anti-HBc upon university entry. Results positive for isolated anti-HBc were reconfirmed by testing for the presence of HBsAg and anti-HBc once more, and further evaluated for anti-HCV, anti-HIV, and HBV DNA status 6 months later. Students were also offered HBV booster vaccinations at that time. Geometric mean titers (GMT) of anti-HBs after one booster dose of HBV were compared between students with isolated anti-HBc and students with HBV naïve status.

RESULTS

The overall prevalence of isolated anti-HBc in our student cohort was 1.2% (21 of 1734). No evidence of occult HBV infection was observed. A "booster" anamnestic response (anti-HBs titer ≥ 10 mIU/mL) was noted in 95% (20 of 21) of subjects with isolated anti-HBc. After re-measurement of anti-HBc, 13 (62%) of the 21 subjects with isolated anti-HBc were reclassified as having resolved HBV infection with a loss of anti-HBs. In the remaining 8 subjects (38%), isolated anti-HBc was determined to be false positive. The HBV status of these 8 subjects was HBV naïve due to the waning-off effect of anti-HBs of the neonatal HBV vaccination. There was no significant difference in anamnestic response to a single HBV booster dose of vaccine between students with isolated anti-HBc (n=13) and those with HBV naïve (n=323) status (GMT 50.6 vs 47.7 mIU/mL, P=0.90).

CONCLUSION

The presence of isolated anti-HBc 18 years after HBV vaccination can be attributed to post-HBV infection with a loss of anti-HBs and to a decline in anti-HBs elicited by vaccine. A single HBV booster dose of vaccine is recommended for subjects with isolated anti-HBc who were fully vaccinated with HBV vaccine as infants. This finding needs to be replicated in further studies with larger cohorts.

Persistence of antibody to hepatitis B surface antigen among vaccinated children in a low hepatitis B virus endemic area

BACKGROUND

A potential problem of hepatitis B immunization is that vaccine-induced antibody to hepatitis B surface antigen (anti-HBs) declines to low levels with age. This study investigated the persistence of anti-HBs in vaccinated children in a low hepatitis B virus (HBV) endemic area.

METHODS

Plasma samples of 938 children between ages of 8 months and 15 years were tested for the presence of anti-HBs.

RESULTS

The seroprotection rate was 60%. Protective antibody level was detected in 65% of children one year after vaccination, and in 30%, 29% and 24% 5, 10 and 15 years after vaccination, respectively. The mean anti-HBs titer declined with post-vaccination time (to 66 mIU/mL in 1 year, 60 mIU/mL in 5 years, 40 mIU/mL in 10 years to 37 mIU/mL in 15 years after vaccination).

CONCLUSIONS

Children vaccinated against HBV during infancy may show low levels of antibody during adolescence. Our data suggest that a booster dose of vaccine may be required in low HBV endemic areas.

Booster dose vaccination for preventing hepatitis B

BACKGROUND

Antibodies against hepatitis B surface antigen (HBs) wane over time after vaccination for hepatitis B (HB); hence, the duration of protection provided by the vaccine is still unknown but may be evaluated indirectly by measuring the anamnestic immune response to booster doses of vaccine.

OBJECTIVES

To assess the benefits and harms of booster dose hepatitis B vaccination for preventing HB infection.

SEARCH STRATEGY

We searched The Cochrane Hepato-biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 4, 2010) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, conference databases, and reference lists of articles to May 2010. We also contacted authors of articles and manufacturers.

SELECTION CRITERIA

Randomised clinical trials addressing anamnestic immune response to booster of HB vaccine five years or more after primary vaccination in apparently healthy participants, vaccinated in a 3-dose or 4-dose schedules of HB vaccine without receiving additional dose or immunoglobulin.

DATA COLLECTION AND ANALYSIS

Two authors made the decisions if the identified publications on studies met the inclusion criteria or not. Primary outcome measures included the proportion with anamnestic immune response in non-protected participants and signs of hepatitis B virus infection. Secondary outcomes were the proportion with local and systemic adverse event events developed following booster dose injection. Weighted proportion were planned to be reported with 95% confidence intervals.

MAIN RESULTS

There were no eligible randomised clinical trials fulfilling the inclusion criteria of this review.

AUTHORS' CONCLUSIONS

We were unable to identify randomised clinical trials on the topic. We need randomised clinical trials to formulate future booster policies for preventing hepatitis B infection.

Economic evaluation of infant and adolescent hepatitis B vaccination in the UK

A Markov model of hepatitis B virus (HBV) disease progression in the UK estimated that 81% of predicted HBV-associated morbidity and mortality could be prevented by universal infant vaccination at a cost of approximately £ 260,000 per QALY gained. Universal adolescent vaccination would be less effective (45% prevented) and less cost-effective (£ 493,000 per QALY gained). Higher HBV incidence rates in males and intermediate/high risk ethnic populations meant it was approximately 3 times more cost-effective to vaccinate these groups. At current vaccine costs a selective infant vaccination programme, based on vaccinating intermediate/high risk ethnic populations would not be considered cost effective. The threshold cost per vaccinated child at which the programme would be considered cost-effective was investigated. Universal infant vaccination would be cost-effective if the average cost of vaccinating each child against HBV, including vaccine and administration costs of all doses, was less than £ 4.09. Given the low cost of vaccination required to make a universal programme cost-effective the most feasible policy in the UK would be to use a suitably priced combined vaccine that included the other antigens in the current infant vaccination schedule.

Immunogenicity of recombinant hepatitis B vaccine: comparison of two different vaccination schedules

BACKGROUND

Neonatal immunization with hepatitis B (HB) vaccine induces protective levels of antibody (anti-HBs > or =10 IU/L) in a majority of vaccines. However, the duration of protection after HB vaccination in infants is unknown. A smaller proportion of children vaccinated beginning at birth with three doses of HB vaccine were found to have protective titers 5-10 years after initial vaccination. Long-term efficacy of HB vaccine depends mainly on peak antibody levels after vaccination, and subjects were observed to have lower levels of antibodies if they received the first dose of vaccine immediately after birth. The aim of our study was to compare the immunogenicity of two different HB vaccine schedules in infants born to HB surface antigen-negative mothers.

METHODS

Anti-HBs titers in infants vaccinated with two different schedules were compared. Infants were vaccinated at 0, 2, and 9 months (group 1) or at 2, 4, and 9 months (group 2). In total, 267 blood samples were analyzed at a mean of 14.20 +/- 2.39 months after the third vaccine dose. Sera were tested for hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) using commercial enzyme immunoassay kits.

RESULTS

The geometric mean titers for anti-HBs were 95.00 and 379.51 IU/L and the rates of anti-HBs more than > or =100 IU/L were 57.7 and 94.9% in group 1 and 2 infants, respectively.

CONCLUSION

Delaying the first dose of the HB vaccine until 2 months after birth produces a higher immune response and can provide longer term protection.

HEPATITIS B AND PREGNANCY, THE SCIENTIFIC BASIS FOR PERINATAL PREVENTION

Hepatitis B and its complications are one of the major global health problems. Around 2 billion individuals are infected by hepatitis B virus (HBV) worldwide, more than 350 million are chronically infected, and approximately 15 to 40 percents of them will develop serious complications such as liver cirrhosis, hepatic failure, or hepatocellular carcinoma (HCC). The worldwide prevalence of chronic HBV infection ranges from 0.1 to 20 percent and varies widely in different geographic areas. According to the prevalence rate, WHO has classified countries into 3 levels: high areas (>8%) such as Africa, Asia, Western Pacific and Middle East; intermediate areas (2–8%) such as South America and Eastern Europe, and low areas (<2%) such as Western Europe, North America, and Australia.

Th2-polarisation of cellular immune memory to neonatal pertussis vaccination

Current infant vaccination against pertussis in North America and Australia requires three doses of vaccines including diphtheria, tetanus and acellular pertussis antigens (DTaP) at 2, 4 and 6 months of age. Interest is growing in the possibility that vaccination at birth might provide earlier protection of infants, but early vaccination also gives rise to concerns over the potential for excessive Th2-polarisation of pertussis-specific T-cell memory profiles. We evaluated this issue as part of a small pilot study comparing infants receiving a monovalent acellular pertussis vaccine (aP) at birth or birth and at 1 month, followed by DTaP at 2, 4 and 6 months with infants receiving DTaP only from 2 months. We compared in vitro Th-memory responses at 8 months and pertussis-specific IgG in serum at 2, 4, 6 and 8 months. Neonatal vaccination elicited earlier IgG responses, but accompanying Th-memory profiles displayed a strong Th2 bias with high IL-5 and IL-13 production. The correlation between T-cell memory profiles and other clinical outcomes should be evaluated in larger trials of neonatal aP vaccine.