Further observations on the immune response to recombinant hepatitis B vaccine after administration to aboriginal and Torres Strait Island children

Measuring quality of hepatitis B care in a remote Australian Aboriginal community: opportunities for improvement

BACKGROUND

Chronic hepatitis B (CHB) infection remains a significant public health issue for Indigenous Australians, in particular for remote communities.

AIM

To evaluate the spectrum of hepatitis B virus (HBV) care provided to a remote Aboriginal community. Measures studied included screening, seroprevalence, vaccination rates and efficacy, and HCC risk and surveillance adherence.

METHODS

A retrospective audit of HBV care received by all permanent residents currently attending a remote Aboriginal Health service. This study was endorsed by both the local Aboriginal Health service and the Aboriginal Health Council of South Australia.

RESULTS

A total of 208 patients attended the clinic, of whom 52% (109) were screened for HBV. Of these, 12% (13) had CHB and 20% (22) had evidence of past infection. Similarly, of the 208 attending patients, complete vaccination was documented in 48% (99). Of the 33 patients with post-vaccination serology, 24% (8) had subtherapeutic (<10 IU/mL) levels of HBsAb. Subtherapeutic HBsAb was independently associated with higher Charlson Comorbidity scores (odds ratio = 17.1; 95% confidence interval 1.2-243.3; P = 0.036). Definitive breakthrough infection was identified in 6% (2) patients. One HBsAg positive patient was identified as needing HCC surveillance, but had not undertaken HCC surveillance.

CONCLUSION

Opportunities to improve the quality of CHB care through increased HBV vaccination, screening and adherence to HCC surveillance were identified. High rates of subtherapeutic vaccine responses and documented breakthrough infection raises concerns about the effectiveness of current CHB vaccines in this population.

Early Childhood Pneumonia Is Associated with Reduced Lung Function and Asthma in First Nations Australian Children and Young Adults

Background: Some but not all previous studies report that pneumonia in children aged less than five years is associated with lower lung function and elevated risk of respiratory disease. To date, none have explored these associations in at-risk populations such as First Nations Australians, whose incidence of early childhood pneumonia is among the highest reported in the world. Methods: This cross-sectional study included 1276 First Nations Australian children/young adults aged 5–25 years recruited from regional/remote Queensland and Northern Territory communities and schools. Associations between pneumonia and both spirometry values and asthma were investigated using linear and logistic regression. Results: Early childhood pneumonia was associated with lower FEV1 and FVC Z-scores, but not FEV1/FVC% Z-scores, when occurring before age three (FEV1 β = −0.42, [95%CI −0.79, −0.04]; FVC β = −0.62, [95%CI −1.14, −0.09]), and between three and five years (β = −0.50, [95%CI −0.88, −0.12]; β = −0.63, [95%CI −1.17, −0.10]), compared to those who never had pneumonia. Similarly, pneumonia occurring when aged before age three years (OR = 3.68, 95%CI 1.96–6.93) and three to five years (OR = 4.81, 95%CI 1.46–15.8) was associated with increased risk of asthma in later childhood. Conclusions: Early childhood pneumonia is associated with lung function deficits and increased asthma risk in later childhood/early adulthood in First Nations Australians. The disproportionate impact of pneumonia on at-risk children must be addressed as a priority.

Long-term impact of infant immunization on hepatitis B prevalence: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis of the long-term impact of infant vaccination on the prevalence of hepatitis B virus (HBV) infection at the population level.

METHODS

We searched online databases for articles reporting comparisons between population cohorts aged ≥ 15 years who were exposed or unexposed to infant HBV immunization programmes. We categorized programmes as universal or targeted to infants whose mothers were positive for hepatitis B surface antigen (HBsAg). We included studies reporting prevalence of hepatitis B core antibody (HBcAb), HBsAg, or both. We evaluated the quality of the study methods and estimated the relative reduction in the prevalence of infection.

FINDINGS

Of 26 studies that met the inclusion criteria, most were from China (20 studies). The prevalence of HBV infection in unvaccinated and universally vaccinated cohorts ranged from 0.6% (116 of 20 305 people) to 16.3% (60/367) and from 0.3% (1/300) to 8.5% (73/857), respectively. Comparing cohorts with universal vaccination to those without vaccination, relative prevalences were 0.24 (95% confidence interval, CI: 0.16-0.35) for HBsAg and 0.23 (95% CI: 0.17-0.32) for HBcAb. For populations with targeted vaccination, relative prevalences were 0.32 (95% CI: 0.24-0.43) and 0.33 (95% CI: 0.23-0.45), respectively.

CONCLUSION

The residual burden of infection in cohorts offered vaccination suggests that longer-term evaluations of vaccination coverage, timeliness and other aspects of programme quality are needed. As HBV-vaccinated infant cohorts reach adulthood, ongoing analysis of prevalence in adolescents and young adults will ensure that elimination efforts are on track.

Prospective clinical trial of hepatitis B vaccination in adults with and without type-2 diabetes mellitus

 Objective: Patients with diabetes mellitus are at increased risk for hepatitis B virus (HBV) infection and its complications. HBV vaccination is recommended for adults with diabetes in the United States and other countries. However, few studies have assessed safety and immunogenicity of hepatitis B vaccine in such patients. We assessed the safety and immunogenicity of recombinant hepatitis B vaccine in subjects with and without diabetes mellitus.

Methods: Prospective, multi-country controlled study in 21 centers (www.clinicaltrials.gov NCT01627340). Four hundred and sixteen participants with Type-2 diabetes and 258 controls matched for age and body mass index (BMI) (2:1 ratio) received 3-doses of HBV vaccine (Engerix-B™, GSK Vaccines, Belgium) according to a 0, 1, 6 months schedule. Antibodies were measured against HBV surface antigen and expressed as seroprotection rates (anti-HBs ≥10mIU/mL) and geometric mean concentration (GMC).

Results: The median age and BMI in patients with diabetes and controls (according-to-protocol cohort) were 54 y and 32.1 kg/m², and 53 y and 30.8 kg/m², respectively. Seroprotection rates (GMCs) one month post-dose-3 were 75.4% (147.6 mIU/mL) and 82.0% (384.2 mIU/mL) in patients with diabetes and controls, respectively. Age-stratified seroprotection rates for patients with diabetes were 88.5% (20–39 years), 81.2% (40–49 years), 83.2% (50–59 years), and 58.2% (≥60 years). The overall safety profile of hepatitis B vaccine was similar between groups.

Conclusions: Hepatitis B vaccine is immunogenic in patients with diabetes and has a similar safety profile to vaccination in healthy controls. Because increasing age was generally associated with a reduction in seroprotection rates, hepatitis B vaccine should be administered as soon as possible after the diagnosis of diabetes.

Responding to Australia's National Hepatitis B Strategy 2010-13: gaps in knowledge and practice in relation to Indigenous Australians

The Australian National Hepatitis B Strategy 2010-13 outlines five priority areas for developing a comprehensive response to the hepatitis B virus (HBV): building partnerships and strengthening community action; preventing HBV transmission; optimising diagnosis and screening; clinical management of people with chronic hepatitis B (CHB); and developing health maintenance, care and support for people with HBV. A scoping study was used to map the main sources and types of evidence available on the epidemiology and natural history of HBV among Indigenous Australians as well as public health responses published since 2001 (January 2001-May 2013). Gaps in current knowledge were identified. While the literature documents the success of universal infant immunisation and indicates the potential for screening initiatives to identify infected and susceptible individuals, prevalence of CHB and hepatocellular cancer remain high in Indigenous Australians. Significant gaps in knowledge and practice were identified in relation to each of the five National Hepatitis B Strategy priority action areas. Successful implementation of the strategy in Indigenous communities and reducing the burden of HBV and hepatocellular cancer in Indigenous Australians will require increased investment in research and knowledge transfer across all priority areas.

Molecular epidemiology of hepatitis B in the Indigenous people of northern Australia

BACKGROUND AND AIM

The hepatitis B surface antigen was first described in the blood of an Indigenous Australian man, yet little is known about its molecular epidemiology in this population, in which it is endemic. The study aimed to determine the clinical and molecular epidemiology of hepatitis B virus (HBV) in Indigenous people from northern Australia.

METHODS

Following ethics approval and informed consent, blood specimens and clinical details from Indigenous adults known to be infected with HBV and who were born and raised in Indigenous communities in northern Australia were obtained. HBV genotypes were determined in isolates with sufficient HBV DNA by polymerase chain reaction by sequencing of the polymerase/surface gene.

RESULTS

Between June 2010 and June 2012, 65 patients were recruited from six different regions of northern Australia. Thirty-two patients (49%) were hepatitis B e-antigen-positive, and 48% were hepatitis B e-antibody-positive. No patients were found to be coinfected with hepatitis C virus or human immunodeficiency virus. Of the 49 samples with sufficient viral load for genotyping, 100% were infected with genotype C4, previously only reported from two Indigenous Australians. All isolates had wild-type polymerase gene sequences despite 14 currently or previously receiving antiviral treatment. The canonical sG145R vaccine-escape variant was detected in the surface antigen of virus from two patients.

CONCLUSIONS

The exclusive HBV genotype in this ancient population is genotype C4. Whole genome sequencing and clinical follow-up of this cohort are in progress, with the aim of exploring the clinical significance of these findings.

Vaccine preventable diseases and vaccination policy for indigenous populations

There are many similarities regarding the health status of Indigenous people in the 4 English-speaking developed countries of North America and the Pacific (United States, Canada, Australia, New Zealand), where they are all now minority populations. Although vaccines have contributed to the reduction or elimination of disease disparities for many infections, Indigenous people continue to have higher morbidity and mortality from many chronic and infectious diseases compared with the general populations in their countries. This review summarizes the available data on the epidemiology of vaccine-preventable diseases in Indigenous populations in these 4 countries in the context of the vaccination strategies used and their impact, with the aim of identifying successful strategies with the potential for wider implementation.

Field evaluation of the efficacy and immunogenicity of recombinant hepatitis B vaccine without HBIG in newborn Vietnamese infants

A study involving more than 2,000 infants was conducted in Vietnam to assess the field effectiveness and immunogenicity of recombinant hepatitis B vaccine given at birth, 1 month, 2 months, without concomitant hepatitis B immune globulin (HBIG). All received a 5 microg dose of H-B-VAX II at birth. Infants born to non-carrier mothers (Group 1; N = 1798) then received 2.5 microg doses at 1 and 2 months of age, while infants of HBeAg-negative (Group 2; N = 125) or HBeAg-positive (Group 3; N = 88) carrier mothers received 5 microg doses. No Group 1 or 2 vaccinees were infected. In Group 3, 12 (14.6%) of 82 infants did become infected (estimated efficacy 84%). 98.0-98.6% of uninfected infants who were tested for anti-HBs developed a seroprotective concentration > or = 10 IU/L. In hyperendemic Vietnam, where routine maternal screening and passive-active prophylaxis of high-risk infants with vaccine plus HBIG is not feasible, administration of vaccine alone to all newborns may control effectively HBV infection.

The investigation of a 'cluster' of hepatitis B in teenagers from an indigenous community in North Queensland

BACKGROUND

In early 1999, five teenagers from the same Indigenous community were notified as having hepatitis B. Hepatitis B vaccine should have been offered to this cohort of teenagers in a 'catch-up' program during the late 1980s when they were of pre-school age.

OBJECTIVES

To determine the vaccination status of residents of the community born between 1981 and 1985 (inclusive) and to ascertain the prevalence of markers of hepatitis B infection and carriage in the incompletely vaccinated teenagers in this cohort.

METHODS

Community health records were examined to identify all residents in the study cohort. Immunisation records were obtained from local hospital records and from a statewide computerised vaccination database. Serological tests for markers of hepatitis B infection and carriage were performed on blood samples from the incompletely vaccinated teenagers.

RESULTS

Only 44% of 235 teenagers who had their vaccination status assessed were fully vaccinated. One hundred and eleven (47%) of the cohort had not received any hepatitis B vaccine. Over 90% of the incompletely vaccinated had been infected with the hepatitis B virus and 26% of these were hepatitis B carriers.

CONCLUSIONS

Despite the availability of an effective hepatitis B vaccine and the recommendation for a catch-up program, the pre-school aged cohort of children at the community were not effectively targeted for vaccination. Hepatitis B remains a consequential infection in Indigenous communities in North Queensland.

IMPLICATIONS

Initiatives to control hepatitis B need to be enhanced within existing maternal and child health, sexual health, alcohol and drug and chronic disease management programs.

The vaccination status of aboriginal and Torres Strait Island children in far north Queensland

A survey was undertaken to ascertain the vaccination status of all 773 Aboriginal and Torres Strait Island children who were born and remained in Far North Queensland during the 1993-94 financial year. Only 42% had received all 15 vaccines scheduled in the first two years of life by their second birthday. More who resided in remote communities were fully vaccinated (64%) by then than those who lived in rural towns (32%) or an urban setting (21%) (p < 0.01). The 445 children who were not fully vaccinated required a median of three vaccines to have been fully vaccinated by the second birthday. Of these, 146 (33%) required only one vaccine, nearly 60% of whom would have been fully vaccinated if they had had the fourth (18-month) dose of diphtheria-tetanus-pertussis (DTP) vaccine. Of the 445, 143 (32%) required five or more vaccines to have been fully vaccinated. Only 26% and 36% of the children received all the vaccines scheduled at six and 12 months of age, respectively, on the same day. However, the eventual uptakes of the three vaccines scheduled at six months of age were very similar (approximately 80%) and simultaneous vaccination with the two vaccines scheduled at 12 months of age would have made a very limited (approximately 4 percentage points) impact on the overall percentage of fully vaccinated children. Considerably more than simple and apparently logical strategies will be required to ensure that Indigenous children in Far North Queensland are adequately vaccinated. A systematic approach, with a careful understanding of the barriers to routine vaccination and a means of prospectively tracking the vaccination status of each child, will be needed if state and national vaccination goals are to be met.