Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is estimated that over 350 million people live with a chronic hepatitis B virus (HBV) infection, claiming over one million deaths per year due to progress of the chronic disease to cirrhosis and/or hepatocellular carcinoma (HCC). An extended program of immunization including hepatitis B vaccine for children under one year of age has been launched in more than 110 countries. Recent studies conclude that mass hepatitis B immunization is effective in preventing HBV infection and has resulted in a decrease in the occurrence of HCC in children living in countries where hepatitis B is endemic. However, the vast majority of infected children live in the poorest developing countries in Africa and Asia that currently cannot afford the vaccine or lack the basic infrastructure necessary to deliver a national immunization service. The Global Alliance for Vaccines and Immunization (GAVI) was established in 1999 as an alliance of WHO, UNICEF, the World Bank, industry, foundations, and other partners to reinvent immunization for the 21st century, by forging a common vision and new ways of working together at global, regional and national levels. WHO recommends global elimination of hepatitis B by universal infant and/or adolescent immunization, but health planners in Sweden and the other Scandinavian countries, the Netherlands and UK have not yet been convinced of the cost-effectiveness of HB-prevention through routine childhood immunization with HB-vaccine. The inclusion of hepatitis B vaccine in already available multivalent vaccines may alter this situation in the future, but until then an intensified vaccination strategy aimed at those groups of individuals that are particularly at risk for hepatitis B should be adopted in accordance with the recommendations of The Swedish National Board of Health (SOSFS 1991:2) and local instructions from the County Medical Officer for Communicable Disease Control.
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PMID:[WHO spearheads global initiative to eradicate hepatitis B]. 1101 26

The Global Alliance for Vaccines and Immunization (GAVI) is seen as a model for the new Global Fund to Fight AIDS, Tuberculosis and Malaria, to be launched early in 2002. We did an assessment in four African countries to report the experiences of ministries of health and their partners in applying to GAVI for funds to strengthen health systems and for new vaccines. Countries welcomed the introduction of hepatitis B vaccine, safe injection equipment, and the financial support to strengthen immunisation programmes. All reported that the pace of the application process was too rapid. District visits revealed low staffing levels, insufficient transport and fuel, poorly functioning cold chains, and infrequent supervision. Information systems were unreliable, which will be an obstacle to GAVI when monitoring and rewarding improvements in immunisation coverage. Also, the high cost of expensive new vaccines will be difficult to sustain if GAVI funding stops at the end of its 5 year commitment. Our study suggests that applications for support and planning for AIDS, tuberculosis, and malaria control under the new Global Fund, will be more complex and demanding on already over-stretched ministries of health. Further, the rapid onset of activities, coupled with uncertainty about the time-scale of donor commitment, could be problematic. A limited and carefully assessed set of initial activities, focusing on where and how to strengthen existing country systems, is more likely to be successful and could provide useful models for scaling-up to larger programmes in different contexts.
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PMID:GAVI, the first steps: lessons for the Global Fund. 1241 33

Hepatitis B is a major global health problem; approximately two billion people are infected with the virus worldwide, despite the fact that safe and efficacious vaccines have been developed and used for nearly 20 years. Prohibitive costs for vaccine purchase and administration restrict uptake in many developing nations. Agencies such as the Global Alliance for Vaccination and Immunization are helping to make current vaccines more available, but reduced costs would greatly aid this effort. Oral delivery is an option to reduce the expense of administering hepatitis B vaccines. It may also improve compliance, and orally delivered vaccines may be more efficacious among poor responders to current vaccines. However, to induce protective efficacy, oral administration may require encapsulation of antigen and delivery of large doses. Plant-based expression systems offer an oral delivery alternative with low production costs, and they also encapsulate the antigen. Some plant-based systems also stabilize antigen and therefore reduce storage and distribution costs. The hepatitis B major surface antigen has been expressed in several plant systems. A variety of regulatory sequences and subcellular targets have been used to achieve expression suitable for early stage clinical trials. However, further increase in expression will be necessary for practical and efficacious products. Appropriate processing can yield palatable products with uniform antigen concentration. The antigen expressed in plant systems shows extensive disulphide cross-linking and oligomerization and forms virus-like particles. Oral delivery of the antigen in plant material can induce a serum antibody response, prime the immune system for a subsequent injection of antigen and give a boosted response to a prior injection. Small scale clinical trials in which the antigen has been delivered orally in edible plant material indicate safety and immunogenicity.
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PMID:Oral hepatitis B vaccine candidates produced and delivered in plant material. 1587 3

Vaccines are a key contributor to public health, especially in developing countries. Despite numerous demonstrations of the cost-effectiveness of immunisation, vaccines spending accounted for only 1.7% of the total pharmaceutical market in 2002, when UNICEF estimated that 34 million children were not reached by routine immunisation, most of them in developing countries. Several international organizations or initiatives, like the Global Alliance for Vaccines and Immunisation (GAVI), have defined a long-term goal of universal immunisation in developing countries. There is an urgent need to estimate the financial resources required to meet this goal. The objective of this study was to anticipate the funding needs for childhood immunisation in developing countries over the 2004-2014 period. The study scope includes all the 75 countries eligible for support from GAVI, and covers existing vaccines that are considered as a priority for GAVI (DTP (diphtheria, tetanus, pertussis), hepatitis B, Haemophilus influenzae type b (as a stand alone presentation or in combination with DTP) and yellow fever) as well as future vaccines (meningitis A and C, rotavirus, human papilloma virus (HPV), malaria, Streptococcus pneumoniae and tuberculosis) likely to be available within the 10-year period. We developed a methodology to estimate the number of doses required, based on disease prevalence and incidence, target populations, introduction dates of new vaccines, coverage dynamics and dosing regimen. The introduction price and price evolution of vaccines over time were modelled, taking into account the type of vaccine, the expected return on investment from vaccine manufacturers and the competitive landscape. Non-vaccine costs (capital costs and non-vaccine recurrent costs) were estimated based on the number of people immunised and number of doses dispensed, using available case studies as a reference. According to the optimal scenario that would consider the provision of all vaccines to all relevant developing countries as soon as they are available, funding requirements to cover the associated total costs over the 10-year period were estimated to be about US$ 30 billion. Vaccines-related costs represent the largest share, with estimated costs of US$ 21 billion (among which 18 billion for new vaccines), the remaining needs being split between capital costs and other recurrent costs. Accounting for the main imponderables (such as delay in vaccines launch compared to industry plans) as well as probable phasing of vaccine introduction in countries, the total costs of immunisation would be reduced to US$ 14-17 billion over the same period. Vaccines-related costs represent the largest share (US$ 7.1-9.3 billion, among which 4.3-6.5 billion for new vaccines). This study advocates for the anticipation of the substantial financial resources needed to (a) purchase and introduce these vaccines in the developing countries in order to reduce the time lag between availability in industrialised and developing countries; and (b) stimulate vaccine researchers and manufacturers to continue research and development of much needed vaccines for the developing world.
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PMID:Financial requirements of immunisation programmes in developing countries: a 2004-2014 perspective. 1597 69

Worldwide, two billion people have been infected with hepatitis B virus (HBV), 360 million have chronic infection, and 600,000 die each year from HBV-related liver disease or hepatocellular carcinoma. This comprehensive review of hepatitis B epidemiology and vaccines focuses on definitive and influential studies and highlights current trends, policies, and directions. HBV can be transmitted vertically, through sexual or household contact, or by unsafe injections, but chronic infections acquired during infancy or childhood account for a disproportionately large share of worldwide morbidity and mortality. Vaccination against HBV infection can be started at birth and provides long-term protection against infection in more than 90% of healthy people. In the 1990s, many industrialized countries and a few less-developed countries implemented universal hepatitis B immunization and experienced measurable reductions in HBV-related disease. For example, in Taiwan, the prevalence of chronic infection in children declined by more than 90%. Many resource-poor nations have recently initiated universal hepatitis B immunization programs with assistance from the Global Alliance for Vaccines and Immunization. Further progress towards the elimination of HBV transmission will require sustainable vaccination programs with improved vaccination coverage, practical methods of measuring the impact of vaccination programs, and targeted vaccination efforts for communities at high risk of infection.
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PMID:Hepatitis B virus infection: epidemiology and vaccination. 1675 44

Hepatitis B virus (HBV) infection is a leading cause of illness and death in China. Approximately 60% of the population has a history of HBV infection, and 9.8% of persons in China are chronically infected with HBV and at risk for premature death from liver disease. Each year, an estimated 263,000 persons in China die from HBV-related liver cancer or cirrhosis, accounting for 37%-50% of HBV-related deaths worldwide. Because most HBV infections occur during infancy or early childhood, when HBV infection is most likely to become chronic, vaccination of infants beginning at birth is the key strategy for preventing chronic HBV infection. This report describes China's progress in increasing coverage among infants with hepatitis B vaccine (HepB) and timely administration of the HepB birth dose (i.e., within 24 hours of birth). Infant vaccination coverage with both the timely birth dose and the complete vaccine series was substantially higher among children born during 2003 than among those born during 1997; timely birth-dose coverage increased from 29.1% to 75.8%, and HepB series completion increased from 70.7% to 89.8%. Furthermore, in economically disadvantaged populations in western and middle provinces targeted by the China-Global Alliance for Vaccines and Immunization (China-GAVI) project, reported coverage with timely HepB birth dose increased from 64% in 2004 to 81% in 2006, and coverage with the complete HepB series increased from 52% in 2001 to 92% in 2006. China has established a goal to reduce chronic HBV infection among children aged <5 years to <1% by 2010. Achieving this goal will require continued commitment to increasing vaccination coverage in impoverished regions and ensuring that infants born at home are vaccinated within 24 hours of birth.
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PMID:Progress in hepatitis B prevention through universal infant vaccination--China, 1997-2006. 1749 90

This paper reviews the experience of the Global Alliance for Vaccines and Immunization (GAVI) in introducing hepatitis B and Haemophilus influenzae type b vaccines in the poorest countries, and explores how financing for immunization has changed since GAVI Fund resources were made available during its first wave of support between 2000 and 2006. The analysis of Financial Sustainability Plans in 50 countries allowed for some of the original funding assumptions of the GAVI approach to be tested against the realities in a wide set of countries, and to highlight implications for future immunization efforts. While the initial GAVI experience with financial sustainability has proved successful through the development of plans, and many countries have been able to both introduce new vaccines and mobilize additional financing for immunization, for future GAVI supported vaccine introduction, some country co-financing of these will be needed upfront for the approach to be more sustainable.
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PMID:Introducing new vaccines in the poorest countries: what did we learn from the GAVI experience with financial sustainability? 1895 34

Development of safe and effective vaccines against human papillomavirus (HPV)-the second vaccine against a major human cancer-is one of the most important medical and public health achievements of this century. As with all new vaccines, HPV is currently expensive and this cost precludes its use in the developing world, which has the greatest burden of disease from HPV-related cancers. Hepatitis B (HB) virus vaccine, which prevents chronic HB infection and related cirrhosis and liver cancer, has been successfully introduced as a routine vaccine for children in 89% of countries, including the poorest. The success of this vaccine provides a model for the introduction of HPV vaccine and control of cervical and other HPV-related cancers and genital warts. Lessons learned from HB vaccine introduction are relevant to our efforts to introduce HPV vaccine globally. As with HB vaccine, introduction of HPV vaccine into national immunization programs and routine use of this vaccine, funded by governments, will be needed to control HPV-related disease on a global basis. Global funding support will be needed to make control a reality for the poorest countries, and the program to accomplish this, the Global Alliance for Vaccines and Immunization (GAVI), has already expressed great interest in including HPV vaccine. For this to occur, the manufacturers will need to dramatically reduce the vaccine price for the poorest developing countries, and tier prices for wealthier developing countries not eligible for GAVI support. Countries will need to decide on the priority of HPV control in the context of other important new vaccines against pneumococcal pneumonia and rotavirus diarrhea.
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PMID:Global implementation of human papillomavirus (HPV) vaccine: lessons from hepatitis B vaccine. 2012 54

In cooperation with Indian health authorities, the GAVI Alliance (GAVI) is introducing Hepatitis B (HepB) vaccination into the immunisation programmes of 11 'better-performing' Indian states. This article describes the concerns and interests of major stakeholders in the programme, including GAVI partners and the Indian government, and summarises Indian debates that have emerged in response to the project, especially on the issue of selective vs. universal immunisation. The article suggests that programme planning should be based on a good knowledge of disease prevalence and the relative importance of perinatal HepB transmission, which would require a comprehensive cross-country study of the epidemiology of HepB among different populations, the relative importance of different transmission routes and the degree of geographical variation in India. Based on this research, further studies could address the feasibility and cost-effectiveness of routine birth-dose administration and selective birth-dose immunisation of infants born to mothers who are chronic HepB virus carriers. The GAVI 'formula' could be strengthened by supporting the basic epidemiological research that is essential to effective programme planning in recipient countries, which are by definition among the world's poorest countries.
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PMID:GAVI and hepatitis B immunisation in India. 2052 Nov 93

Increased international support for both research into new vaccines and their deployment in developing countries has been evident over the past decade. In particular, the GAVI Alliance has had a major impact in increasing uptake of the six common infant vaccines as well as those against hepatitis B and yellow fever. It further aims to introduce pneumococcal and rotavirus vaccines in the near future and several others, including those against human papillomavirus, meningococcal disease, rubella and typhoid not long after that. In addition, there is advanced research into vaccines against malaria, HIV/AIDS and tuberculosis. By 2030, we may have about 20 vaccines that need to be used in the developing world. Finding the requisite funds to achieve this will pose a major problem. A second and urgent question is how to complete the job of global polio eradication. The new strategic plan calls for completion by 2013, but both pre-eradication and post-eradication challenges remain. Vaccines will eventually become available beyond the field of infectious diseases. Much interesting work is being done in both autoimmunity and cancer. Cutting across disease groupings, there are issues in methods of delivery and new adjuvant formulations.
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PMID:Vaccines and future global health needs. 2189 48


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