Hepatitis B vaccine and central nervous system demyelinating diseases. Viral Hepatitis Prevention Board

Prevention of Hepatitis B Virus Infection and Liver Cancer

Hepatocellular carcinoma (HCC) is one of the five leading causes of cancer death in human. Hepatitis B virus (HBV) is the most common etiologic agent of HCC in the world. Prevention is the best way to control cancer. There are three levels of liver cancer prevention, i.e., primary prevention by HBV vaccination targeting the general population starting from birth dose, secondary prevention by antiviral agent for high-risk subjects with chronic HBV infection, and tertiary prevention by antiviral agent to prevent recurrence for patients who have been successfully treated for liver cancer. Primary prevention by hepatitis B vaccination is most cost effective, the cancer preventive efficacy support it as the first successful example of cancer preventive vaccine in human. Addition of hepatitis B immunoglobulin immediately after birth and antiviral agent during the third trimester of pregnancy to block mother-to-infant transmission of HBV are existing or possible emerging strategies to enhance the prevention efficacy of HBV infection and its related liver cancer. Secondary prevention with current antiviral agents may reduce the risk or delay the onset of HCC development, but could not eradicate HBV infection and HCC. Better antiviral therapeutic agents are needed for better secondary prevention.

Prevention of Hepatitis B Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices

HEPATITIS B VIRUS (HBV) IS TRANSMITTED VIA BLOOD OR SEXUAL CONTACT. PERSONS WITH CHRONIC HBV INFECTION ARE AT INCREASED RISK FOR CIRRHOSIS AND LIVER CANCER AND REQUIRE MEDICAL CARE. THIS REPORT UPDATES AND SUMMARIZES PREVIOUSLY PUBLISHED RECOMMENDATIONS FROM THE ADVISORY COMMITTEE ON IMMUNIZATION PRACTICES (ACIP) AND CDC REGARDING THE PREVENTION OF HBV INFECTION IN THE UNITED STATES. ACIP RECOMMENDS TESTING ALL PREGNANT WOMEN FOR HEPATITIS B SURFACE ANTIGEN (HBSAG), AND TESTING HBSAG-POSITIVE PREGNANT WOMEN FOR HEPATITIS B VIRUS DEOXYRIBONUCLEIC ACID (HBV DNA); ADMINISTRATION OF HEPB VACCINE AND HEPATITIS B IMMUNE GLOBULIN (HBIG) FOR INFANTS BORN TO HBV-INFECTED WOMEN WITHIN 12 HOURS OF BIRTH, FOLLOWED BY COMPLETION OF THE VACCINE SERIES AND POSTVACCINATION SEROLOGIC TESTING; UNIVERSAL HEPATITIS B VACCINATION WITHIN 24 HOURS OF BIRTH, FOLLOWED BY COMPLETION OF THE VACCINE SERIES; AND VACCINATION OF CHILDREN AND ADOLESCENTS AGED <19 YEARS WHO HAVE NOT BEEN VACCINATED PREVIOUSLY. ACIP RECOMMENDS VACCINATION OF ADULTS AT RISK FOR HBV INFECTION, INCLUDING UNIVERSAL VACCINATION OF ADULTS IN SETTINGS IN WHICH A HIGH PROPORTION HAVE RISK FACTORS FOR HBV INFECTION AND VACCINATION OF ADULTS REQUESTING PROTECTION FROM HBV WITHOUT ACKNOWLEDGMENT OF A SPECIFIC RISK FACTOR. THESE RECOMMENDATIONS ALSO PROVIDE CDC GUIDANCE FOR POSTEXPOSURE PROPHYLAXIS FOLLOWING OCCUPATIONAL AND OTHER EXPOSURES. THIS REPORT ALSO BRIEFLY SUMMARIZES PREVIOUSLY PUBLISHED AMERICAN ASSOCIATION FOR THE STUDY OF LIVER DISEASEST GUIDELINES FOR MATERNAL ANTIVIRAL THERAPY TO REDUCE PERINATAL HBV TRANSMISSION.

Prevention of hepatitis B virus infection and liver cancer

Hepatocellular carcinoma (HCC) is one of the five leading causes of cancer death in human. Hepatitis B virus (HBV) is the most common etiologic agent of HCC in the world, particularly in areas prevalent for HBV infection such as Asia, Africa, southern part of Eastern and Central Europe, and the Middle East. Risk factors of HBV-related HCC include (1) viral factors-persistent high viral replication, HBV genotype C or D, pre-S2 or core promoter mutants; (2) host factors-older age (>40 years old) at HBeAg seroconversion, male gender; (3) mother-to-infant transmission; and (4) other carcinogenic factors-smoking, habitual use of alcohol, etc. Prevention is the best way to control cancer. There are three levels of liver cancer prevention, i.e., primary prevention by HBV vaccination targeting the general population, secondary prevention by antiviral agent for high-risk subjects with chronic HBV infection, and tertiary prevention by antiviral agent to prevent recurrence for patients who have been successfully treated for liver cancer. Primary prevention by hepatitis B vaccination is most cost effective. Its cancer preventive efficacy supports it as the first successful example of cancer preventive vaccine in human. This experience can be extended to the development of other cancer preventive vaccine. Careful basic and clinical research is needed to develop ideal vaccines to induce adequate protection. Understanding the main transmission route and age at primary infection may help to set the optimal target age to start a new cancer preventive vaccination program. Besides timely HBV vaccination, the earlier administration of hepatitis B immunoglobulin immediately after birth, and even antiviral agent during the third trimester of pregnancy to block mother-to-infant transmission of HBV are possible strategies to enhance the prevention efficacy of HBV infection and its related liver cancer.

The clinician's guide to the anti-vaccinationists' galaxy

In this paper we briefly review three common immunological misconceptions that feature prominently among anti-vaccinationists, and in turn, fuel patient and parental concerns, questions, and fears about vaccines. In particular, this Perspective covers a brief history of the anti-vaccine movement, and three common false immunological claims, namely, concerns over "antigenic overload," the induction of autoimmunity by vaccines, and the value of "natural immunity" versus vaccine-induced immunity. This is followed by a review of the harms that have been done by anti-vaccinationists, and a call to action. Regardless of the motivation behind such fears and anti-vaccine sentiment, common fears and concerns relevant to vaccines are evident and therefore are the subject of this Perspective. It is hoped that clinicians will find this information useful in answering concerns and misconceptions about vaccines, and in educating their patients.

Meningitis: is a major cause of disability amongst Papua New Guinea children?

PURPOSE

This article is intended to focus on the need for the use of rehabilitation services, for children with meningitis in Papua New Guinea, which is one of largest developing country in The Pacific with diverse culture and landscape. Meningitis is the fifth leading disease that results in disability in the country. The first line of treatment is usually antibiotics, administration of vaccination is also recommended. Currently community based rehabilitation workers and Physiotherapist offer the rehabilitation services. There is a need for the other rehabilitation professionals and appropriate education to the CBR workers, caregivers for providing effective Rehabilitation.

METHOD

Articles related to meningitis were recruited through various electronic database such as Ovid SP, MEDLINE, CINHAL, Google Scholar and HINARI and EBSCOhost for full text. The search includes journal articles, editorials, research reports, systematic reviews and books.

RESULTS

The neurological sequelae resulting from meningitis are increasing. There is a need for Hib vaccination to reduce the rate of mortality. Physiotherapists are new professionals that emerged since 2006 and are assisting in reducing the motor and neurological disability.

CONCLUSIONS

A multidisciplinary approach is required to manage the child with meningitis. Adequate knowledge, resources and assistance about the condition among the health professionals, carers and teachers would enable the children to achieve the quality of life.

Hepatitis B vaccination: disease and cancer prevention-a Taiwanese experience

Prevention is most cost effective toward successful control of hepatitis B virus (HBV) infection and its complications. It is particularly urgent where HBV infection and hepatocellular carcinoma (HCC) are prevalent. To achieve better results of primary HCC prevention globally, higher world coverage rates of HBV vaccine, better strategies against breakthrough infection/nonresponder, and good long-term protection are needed. With the universal hepatitis B vaccination program starting from neonates in most countries, HBV infection and its complications will be further reduced in this century. An effective decline in the incidence of HCC in adults is expected in the near future. The concept of a cancer preventive vaccine, using HBV as an example, can be applied further to other infectious agents and their related cancers.

Trends affecting the future of vaccine development and delivery: the role of demographics, regulatory science, the anti-vaccine movement, and vaccinomics

Important scientific, cultural, temporal, and secular issues impact the development of, and delivery of vaccines. In this paper we discuss the impact of demographics, regulatory science, the anti-vaccine movement, and finally the impact of the new biology and individualized medicine, which we call vaccinomics, on vaccine development and delivery. A description of the issues and how they have, are, or should be impacting vaccinology is provided, and hopefully will result in increased attention and discussion among vaccinologists. These issues have been under-valued, under-discussed, and in some cases, ignored. We hope that discussion of these issues will result in changes in how we develop, and how we communicate those developments, to the public.

Cancer prevention by vaccination against hepatitis B

Chronic inflammation caused by persistent infection is closely related to a number of cancers; these include hepatitis B (HBV) or C and hepatoma, human papilloma virus and cervical cancer, and Helicobacter pylori and gastric cancer. The first evidence of cancer prevention by vaccination in humans was provided by HBV vaccination in infants. Chronic HBV is related to approximately 60%-90% of hepatocellular carcinomas (HCC) in adults and nearly 100% of childhood HCC in areas endemic for HBV infection. The first universal HBV vaccination program was launched in Taiwan and has continued for more than 20 years. Three or four doses of HBV vaccine were given to all infants starting from the first week of life. In addition, infants of high-risk mothers (with positive hepatitis B e antigen or high HBsAg titers) were given hepatitis B immunoglobulin within 24 h after birth. At 20 years after the launch of the HBV vaccination program in Taiwan, chronic HBV infection (HBsAg seropositive) rates in the general population below 20 years of age have revealed a remarkable reduction from 10%-17% before the vaccination program to 0.7%-1.7% after the program. HCC incidence rate in children 6-14 years old also fell from 0.52-0.54 to 0.13-0.20 per 100,000 (R.R. = 0.25-0.36). HCC prevention failure is mainly related to vaccine failure to prevent chronic HBV infection. The causes of vaccine failure have included intrauterine infection, vaccine escape mutants, genetic hyporesponsiveness, and poor compliance. Future efforts to reduce vaccine failure will improve the efficacy of liver cancer prevention by HBV vaccination. The experience of HCC prevention by HBV immunization may be applied to the prevention of other infection-related cancers.

Invasive pneumococcal disease in children<5 years of age in rural Mozambique

OBJECTIVES

To estimate the incidence and epidemiological characteristics of invasive pneumococcal disease (IPD) in children<5 years of age living in a rural area of southern Mozambique.

METHODS

As part of the clinical management of children admitted to Manhiça District Hospital, prospective surveillance for invasive bacterial disease was conducted from June 2001 to May 2003. The level of antibiotic resistance of the isolates was also analysed.

RESULTS

Pneumococcus was the most commonly isolated bacterium, accounting for 212 episodes. The estimated crude incidence rate of IPD in the study area among children<5 years of age was 416/100,000 per child-year at risk. The youngest age group (<3 months) had the highest incidence (779/100,000). Cases were detected during both rainy and dry seasons. The most common clinical diagnosis was pneumonia, made in 146/212 (69%) of the episodes of IPD. The overall case fatality rate was 10%, being highest among children with pneumococcal meningitis (5/9=56%). Pneumococcal isolates were highly susceptible to penicillin (86% susceptible and 14% with intermediate resistance) and chloramphenicol (98% susceptible). In contrast, up to 37% of the isolates tested were non-susceptible to cotrimoxazole.

CONCLUSIONS

Incidence rates of IPD and associated mortality shown in this study highlight the need for pneumococcal vaccines in rural Africa, which must be effective in infants and young children.

Vaccine safety controversies and the future of vaccination programs

In the years following the hepatitis B vaccination/multiple sclerosis controversy, a number of new issues regarding vaccine safety have been raised, in some cases leading to more debate and confusion. Against this background, an international group of experts was convened to review the current points of view concerning the use of thimerosal as a preservative and its potential risks; the suggested link between thimerosal-containing vaccines and acute lymphoblastic leukemia; the alleged association between aluminum-containing vaccines/macrophagic myofasciitis and general systemic complaints; a possible link between vaccination and autoimmune pathology; and a hypothetical link between measles-mumps-rubella vaccination and autism. At present, there are no data to conclude that childhood vaccines, and in particular hepatitis B vaccine, pose a serious health risk or justify a change in current immunization practice. However, vaccine "scares" continue to have an international impact on immunization coverage. Creating a positive environment for immunization can be achieved by repositioning the value of vaccines and vaccination, supported by evidence-based information. The role of international organizations, the media, and the industry in the implementation of communication strategies was discussed and the impact of litigation issues on vaccination was evaluated. The Viral Hepatitis Prevention Board confirms its commitment to current recommendations for universal and risk group hepatitis B vaccination and further encourages the conduct of vaccine safety studies and the dissemination of their results.

Decreasing incidence of hepatocellular carcinoma among children following universal hepatitis B immunization

Hepatocellular carcinoma (HCC) is one of the 10 most common malignant tumors worldwide. Chronic infection with hepatitis B or C virus is closely related to hepatocarcinogenesis. The outcome of current therapies for HCC is not satisfactory. Prevention is the best way to control HCC. Among the various strategies of HCC prevention, immunization against hepatitis B virus infection is the most effective. Universal hepatitis B immunization has proved to be effective in reducing the incidence of HCC to 1/4-1/3 of that in children born before the hepatitis B vaccination era in Taiwan. The problems we face in achieving global control of hepatitis-related HCC include: (1) no effective vaccine for the prevention of hepatitis C and its related HCC; (2) no immunization program for hepatitis B in areas with inadequate resources; (3) poor compliance to the immunization program as a result of ignorance, anxiety, or poverty; and (4) vaccine failure. Integration of the hepatitis B vaccination program into the expanded program of immunization for all infants throughout the world will be most urgent and important for HCC control. The reduction of the incidence of HCC will be seen in adults 30-40 years of age after the launch of the universal hepatitis B vaccination program. This concept of cancer vaccine can be applied to other infectious agents and their related cancers.

Recent differing expert opinions regarding the safety profile of hepatitis B vaccines: is there really a controversy?

Recent papers in Expert Opinion on Drug Safety arrived at different conclusions about the safety of hepatitis B vaccines. In one of these, review of the epidemiological literature failed to confirm the serious allegations raised with respect to vaccination. In the other, review of case reports and the authors' analytical method suggested serious adverse events are associated with the vaccine. In particular, they suggested a strong relationship with multiple sclerosis, the adverse event that has been the focus of several epidemiological investigations and has been found not to be related to vaccination. The method, using data from reported cases, attempted to compute relative and attributable risks using adult Td vaccine as a comparator. The authors made errors in assumptions about the data, including inappropriate use of controls and inappropriate application of epidemiology, rendering the conclusions invalid. Passive reporting data should be analysed with care and used only for hypothesis generation - anything more requires robust epidemiological study.

Afebrile convulsion in an adult after recombinant hepatitis B vaccination

Vaccination against HBV is important in order to reduce the incidence of HBV infection. Although the HBV vaccine is among the safest of all vaccines, vaccination against HBV has been associated with side-effects. Herein we present a case of afebrile convulsion after recombinant HBV vaccination.

Hepatitis B vaccine and risk of multiple sclerosis

The possibility that hepatitis B vaccine may cause or exacerbate multiple sclerosis stems from several case reports of onset or recurrence of symptoms of CNS demyelination shortly following vaccination. It is difficult, however, to infer causation from individual case reports since they may simply represent coincidental temporal associations with vaccination. There is only weak, nonspecific evidence to support the biological plausibility of an association between hepatitis B vaccine and multiple sclerosis. Epidemiological studies have found that hepatitis B vaccine does not increase the risk of developing multiple sclerosis or cause exacerbations. The US Institute of Medicine and other review panels have concluded that the evidence favors rejection of a causal association between hepatitis B vaccine and multiple sclerosis.

Global control of hepatitis B virus infection

Worldwide about 350 million people are chronic carriers of the hepatitis B virus (HBV). The infection can cause acute and chronic liver disease including cirrhosis and hepatocellular carcinoma (HCC). Hepatocellular injuries of HBV infection are predominantly immune-mediated, and the natural history of chronic infection can be divided into three phases based on virus-host interactions-namely, immune tolerance, immune clearance, and viral integration phases. Four serotypes (adw, ayw, adr, and ayr) and seven genotypes (A to G) of HBV have been identified, and they show some distinct geographic distributions. The HBV genotypes may have clinical relevance and are currently under investigation. On the basis of disease burden and the availability of safe and effective vaccines, the WHO recommended that by the end of the 20th century hepatitis B vaccine be incorporated into routine infant and childhood immunisation programmes for all countries. The efficacy of universal immunisation has been shown in different countries, with striking reductions of the prevalence of HBV carriage in children. Most important, hepatitis B vaccination can protect children against HCC and fulminant hepatitis, as has been shown in Taiwan. Nevertheless, the implementation of worldwide vaccination against HBV requires greater effort to overcome the social and economic hurdles. Safe and effective antiviral treatments are available but are still far from ideal, a situation that, hopefully, will be improved soon. With hepatitis B immunisation, the global control of HBV infection is possible by the end of the first half of 21st century.

The science of evaluation of adverse events associated with vaccination

All vaccines cause some adverse events; serious adverse events are rare. Causal associations between a vaccine and an adverse event rarely can be determined by specific tests such as identifying a vaccine agent in the affected tissue of patients. In the absence of such data, epidemiologic studies can be used to determine if the risk of the disorder is increased in vaccinated compared to unvaccinated individuals. Common mistakes include assuming a causal relationship based on a temporal association only or a series of affected patients. Careful studies have demonstrated that many hypothesized causal associations between vaccines and adverse events were not substantiated. False assumptions regarding causality are likely to occur for illnesses without a carefully defined etiology or pathogenesis.

Challenges to vaccine safety

The end of the 20th century saw the realization of a goal that was previously only dreamed about: the near elimination of many deadly infectious diseases through universal vaccination. As one disease after another has been driven from memory, it is vaccination programs themselves that have come to occupy the public's mind. With increased scrutiny comes the promise that vaccines will become even safer, but there is also the threat that ill-founded concerns will result in reduced immunization rates, and diseases will resurge. This article reviews scientific data relating to current vaccine safety concerns.

Vaccine safety--vaccine benefits: science and the public's perception

The development of cowpox vaccination by Jenner led to the development of immunology as a scientific discipline. The subsequent eradication of smallpox and the remarkable effects of other vaccines are among the most important contributions of biomedical science to human health. Today, the need for new vaccines has never been greater. However, in developed countries, the public's fear of vaccine-preventable diseases has waned, and awareness of potential adverse effects has increased, which is threatening vaccine acceptance. To further the control of disease by vaccination, we must develop safe and effective new vaccines to combat infectious diseases, and address the public's concerns.

Understanding those who do not understand: a brief review of the anti-vaccine movement

Vaccines and the ability to prevent morbidity and mortality due to infectious diseases have been one of the greatest public health success stories. On a global level, it is one of the few cost-effective medical measures that result in universal benefit. Despite this, there is evidence of a growing anti-vaccine movement. In turn, this has, in some cases, resulted in major disruptions in vaccine programs, with resultant needless morbidity and mortality. Of interest are the factors that seem to contribute to the current trend of anti-vaccine sentiment. This paper will examine the current anti-vaccine movement and provide current examples. Finally, a review of suggestions for dealing with the anti-vaccine movement will be presented.

Host-pathogen interactions in emerging and re-emerging infectious diseases: a genomic perspective of tuberculosis, malaria, human immunodeficiency virus infection, hepatitis B, and cholera

On exposure to a pathogen, a host may resist infection, become subclinically infected, or progress through several stages from mild to severe infection. Chronic sequelae may or may not occur. Host factors, particularly host genes, influence many of these stages. We have used a model of the continuum of pathogenesis of infectious diseases to consider the effect of host genes on five pathogens of significant public health burden: Mycobacterium tuberculosis, Plasmodium species, human immunodeficiency virus, hepatitis B virus, and Vibrio cholerae. The relationships between these infections and polymorphisms in human leukocyte antigen, cytokines, other immune response, or pathogen receptor genes are reviewed. We discuss gene-gene interactions and their effects in complex settings, such as coinfections with several pathogens. Priorities for prevention and control of these pathogens include vaccines and antimicrobial drugs. Research on how host genes can influence vaccine responses and the efficacy of drugs or other interventions, as well as further research into the relationship of host genes to infectious disease outcomes, may lead to new strategies for prevention and control.

Mucosal immunization against hepatitis B virus by intranasal co-administration of recombinant hepatitis B surface antigen and recombinant cholera toxin B subunit as an adjuvant

Recombinant cholera toxin B subunit (rCTB) produced by Bacillus brevis carrying pNU212-CTB has been previously found to be a potent mucosal adjuvant to aluminium-non-adsorbed tetanus toxoid (nTT) and diphtheria toxoid (nDT) co-administered intranasally, and the possibility of needle-free inoculation of these vaccines with rCTB has been suggested. In this paper we examined the potentiality of rCTB as a mucosal adjuvant to aluminium-non-adsorbed yeast-derived recombinant hepatitis B surface antigen (rHBs) being a particulate antigen when administered intranasally with rCTB. In-house ELISA showed that a mixture of rHBs (1 or 5 microg) and rCTB (10 microg) elevated not only systemic responses but also mucosal immune responses at the nasal cavity, the lung, the saliva, the small intestine and the vagina against rHBs, and these could be further increased with higher doses of antigen. With antibody isotypes of IgG, there were equally high levels of serum HBs-specific IgG1, IgG2a and IgG2b antibodies and induction of mixed Th1- and Th2-type responses was considered to occur in combination of rHBs and rCTB. Serum anti-HBs titres in almost all mice obtained from sandwich EIA using a commercial kit were higher than 1000 milli-international units ml(-1) (mIU ml(-1)). These results show that rCTB is also very effective as a mucosal adjuvant for a particulate antigen like rHBs, as well as soluble antigens like nTT and nDT reported previously, suggesting the possibility of intranasal immunization with rHBs plus rCTB in humans.

Safety of routine childhood vaccinations. An epidemiological review

Immunisations have been one of the most cost-effective public health interventions in human history. Despite remarkable progress, several challenges face immunisation programs worldwide. Paradoxically, despite vaccines' clear effectiveness in reducing risks of diseases that were previously widely prevalent and caused substantial morbidity and mortality, current vaccination policies have become increasingly controversial due to concerns about vaccine safety. Vaccines, like other pharmaceutical products, are not entirely risk-free. While most known adverse effects are minor and self-limited, some vaccines have been associated with very rare but serious adverse effects. Because such rare effects are often not evident until vaccines come into widespread use, ongoing surveillance programs to monitor vaccine safety are needed. Such monitoring will be essential if the public is to accept the increasing number of new vaccines made possible by biotechnology. The interpretation of data from vaccine safety research is complex and is associated with some uncertainty. Effectively communicating this uncertainty and continuing to improve understanding of rare risks and risk factors are essential for "mature" immunisation programs to maintain public confidence in immunisations.

Is there a causal link between hepatitis B vaccination and multiple sclerosis?

After the publication of case reports of hepatitis B vaccinees with onset or relapse of multiple sclerosis (MS), followed by a media-driven scare campaign in France, the perception that hepatitis B vaccine causes MS has developed. This has led to a fall in the acceptance of hepatitis B vaccination particularly in French-speaking communities which was accelerated by court decisions in favour of vaccination "victims" and the suspension of routine vaccination of pre-adolescents in French schools as a "precautionary measure". This situation has arisen in spite of the absence of scientific data to support a causal link between vaccination and multiple sclerosis. In this article, initially written to inform and reassure employees of one of the vaccine manufacturers, the epidemiological importance of hepatitis B and current knowledge on the aetiology of MS are described. All available data that may throw light on the hypothesis that hepatitis B vaccination is causally linked to MS was reviewed. The conclusion reached on the basis of available data is that the most plausible explanation for the observed temporal association between vaccination and MS is that it is a coincidental association. It is now important to rebuild public confidence in hepatitis B vaccine as well as in vaccination in general.

Current update of pediatric hepatitis vaccine use

Vaccines are now available for the prevention of hepatitis A and hepatitis B. In this article, biologics are reviewed with special attention to their use in the pediatric patient. Special attention is paid to issues that developed in 1999. For hepatitis A vaccine, it is the change in US recommendations regarding increased use in higher-risk US locations. For hepatitis B vaccine, it is the concern about toxicity, real or imagined.

School-based hepatitis B vaccination programme and adolescent multiple sclerosis

We investigated multiple sclerosis in adolescents in British Columbia before and after a hepatitis B vaccination programme was begun. There was no evidence of a link between hepatitis B vaccination and multiple sclerosis or other demyelinating disease.

Prospects for hepatitis B virus eradication and control of hepatocellular carcinoma

Hepatitis B virus infection is the most common cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma worldwide. In areas hyperendemic for HBV infection, the related complications occur mostly during adulthood. However, nearly half of all primary infection in chronic carriers occurs in the perinatal period through maternal transmission, the other half arising from horizontal transmission mainly through intrafamilial spread or injection using unsterilized needles. A universal vaccination programme is better than immunization for at-risk groups. Hepatitis B vaccination should be integrated into the Expanded Programme on Immunization in children. Universal immunization against hepatitis B virus has proved to be effective in reducing the hepatitis B carrier rate to one-tenth of the prevalence before the vaccination programme in highly endemic areas, and the incidence of hepatocellular carcinoma in children has also been shown to be significantly reduced. Continued efforts to implement universal vaccination programmes worldwide will very likely reduce the incidence of hepatitis B virus-related diseases, particularly liver cirrhosis and hepatocellular carcinoma.

Over a decade of experience with a yeast recombinant hepatitis B vaccine

Experience with the yeast recombinant hepatitis B vaccine Engerix-B now exceeds 10 years. We reviewed published studies on this vaccine. These show the vaccine to be safe, causing mostly only minor local symptoms and to be highly immunogenic both in monitored clinical trials and under field conditions. Engerix-B consistently elicits high geometric mean antibody titres and a high protective efficacy has been established in three groups at high-risk of hepatitis B infection, homosexual men, institutionalised mentally handicapped subjects and neonates of chronic carrier mothers. The profile of the recombinant hepatitis B vaccine in certain high-risk groups and immuno compromised people is discussed. Finally we present updated post marketing surveillance data based on 496 million distributed doses of vaccine.