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

(1) A few exceptional but serious cases have raised the possibility that hepatitis B vaccination could trigger or exacerbate demyelinating and autoimmune diseases. (2) Epidemiological data, i.e. three cohort studies and five case-control studies, showed no increased risk of demyelinating disease after hepatitis B vaccination. Another case-control study showed a significant link between multiple sclerosis and hepatitis B vaccination. Any increase in risk (if indeed there is one) probably affects only a small minority of vaccine recipients. But these few cannot be identified before vaccination. (3) Hepatitis B vaccination carries a very low risk of anaphylactic reactions (estimated incidence less than 1 case per 100 000 injections). (4) A few cases of haematological, rheumatological and autoimmune disturbance have been linked to hepatitis B vaccination. Appropriate epidemiological studies are needed to determine whether these links are causal. (5) In practice, hepatitis B vaccination has a favourable risk-benefit balance in non-immunised subjects who are at risk of contracting hepatitis B.
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PMID:Systemic adverse effects of hepatitis B vaccines are rare. 1561 43

Demyelination events or multiple sclerosis following hepatitis B virus (HBV) vaccination have been reported. We therefore compared the T-cell response to HBsAg in patients with CNS demyelination following HBV vaccination and in HBV-vaccinated healthy individuals. Our data showed no differences in terms of T-cell proliferation or cytokine production between these groups and may help to allay concerns that HBV vaccination might trigger a deleterious immune response.
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PMID:Hepatitis B vaccination and central nervous system demyelination: an immunological approach. 1572 74

Reports of multiple sclerosis developing after hepatitis B vaccination have led to the concern that this vaccine might be a cause of multiple sclerosis in previously healthy subjects. Some articles evidenced that minor Hepatitis B virus (HBV) polymerase proteins could be produced by alternative transcriptional or translational strategies. Their detection is very difficult because they are in minute concentration and probably enzymatically inactive, however, it was shown that they could be exposed on the outside of the virus particles and also be immunogenic. In addition, HBV polymerase shares significant amino acid similarities with the human myelin basic protein. We hypothesise that some of the apparent adverse reactions to the vaccine could be due to a process called of molecular mimicry, the HBV polymerase, which could be a contaminant in the recombinant or plasma-derived vaccines, could act as autoantigens and induce autoimmune demyelinating diseases such as multiple sclerosis.
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PMID:Multiple sclerosis and hepatitis B vaccination: could minute contamination of the vaccine by partial hepatitis B virus polymerase play a role through molecular mimicry? 1590 38

Following allegations that Hepatitis B vaccination causes or triggers multiple sclerosis (MS), several epidemiological studies have been conducted to evaluate the association between MS and vaccination. In one study conducted in the US, a significant protective effect on the development of MS was observed for tetanus immunization. We reviewed the medical literature and found two additional recent studies, as well as several older studies, which also observed a significant protective effect of tetanus immunization on the development or progression of MS. Furthermore, decreased humoral and cellular immunity to tetanus toxoid has been observed among MS patients. We postulate that naturally acquired or vaccine-induced immunity to tetanus has a protective effect against the development and progression of MS. We also postulate that this link to tetanus is in part responsible for the gender, age, geographic and socio-economic distribution of MS, as well as its pattern among migrants. The biological basis for this protective effect could be an unspecific boost of bystander suppression of auto-immunity as shown for other infections. Our hypothesis can be tested in several ways. The simplest approach would be to compare tetanus exposure and MS occurrence on a population level. Stronger support would come from the re-analysis of previous studies that have information at the individual level on both tetanus exposure, whether induced or natural, and on the development of MS. Laboratory evidence could be sought by testing the effect of tetanus toxoid on experimental allergic encephalomyelitis, the experimental animal model of MS.
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PMID:Immunity to tetanus is protective against the development of multiple sclerosis. 1602

In spite of a huge number of reports of severe hazards after injection of hepatitis B vaccine (HBV), the issue is regularly raised that no mechanism is available for the development of central demyelinating disorders such as multiple sclerosis (MS). A number of convergent facts, however, suggests that the manufacturing process could introduce HBV polymerase as a contaminant, and then trigger an auto-immune process against myelin in some vaccinated subjects. Of great significance, this hypothesis is likely to give the missing link to account for the considerable body of clinical and epidemiological evidence documenting that, for a drug used with a preventive purpose, HBV has an unusual potential to induce central neurological disorders amongst others unwanted side-effects.
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PMID:Multiple sclerosis and hepatitis B vaccination: adding the credibility of molecular biology to an unusual level of clinical and epidemiological evidence. 1617 57

Hepatitis B infection is one of the most important causes of acute and chronic liver disease. During the 1980s, genetically engineered hepatitis B vaccines (HBVs) were introduced in the United States. A large-series of serious autoimmune conditions have been reported following HBVs, despite the fact that HBVs have been reported to be "generally well-tolerated." A case-control epidemiological study was conducted to evaluate serious autoimmune adverse events prospectively reported to the vaccine adverse events reporting system (VAERS) database following HBVs, in comparison to an age, sex, and vaccine year matched unexposed tetanus-containing vaccine (TCV) group for conditions that have been previously identified on an a priori basis from case-reports. Adults receiving HBV had significantly increased odds ratios (OR) for multiple sclerosis (OR = 5.2, p < 0.0003, 95% Confidence Interval (CI) = 1.9 - 20), optic neuritis (OR = 14, p < 0.0002, 95% CI = 2.3 - 560), vasculitis (OR = 2.6, p < 0.04, 95% CI = 1.03 - 8.7), arthritis (OR = 2.01, p < 0.0003, 95% CI = 1.3 - 3.1), alopecia (OR = 7.2, p < 0.0001, 95% CI = 3.2 - 20), lupus erythematosus (OR = 9.1, p < 0.0001, 95% CI = 2.3 - 76), rheumatoid arthritis (OR = 18, p < 0.0001, 95% CI = 3.1 - 740), and thrombocytopenia (OR = 2.3, p < 0.04, 95% CI = 1.02 - 6.2) in comparison to the TCV group. Minimal confounding or systematic error was observed. Despite the negative findings of the present study regarding the rare serious adverse effects of HBVs, it is clear that HBV does, indeed, offer significant benefits, but it is also clear that chances of exposure to hepatitis B virus in adults is largely life-style dependent. Adults should make an informed consent decision, weighing the risks and benefits of HBV, as to whether or not to be immunized.
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PMID:A case-control study of serious autoimmune adverse events following hepatitis B immunization. 1620 12

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.
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PMID:Vaccine safety controversies and the future of vaccination programs. 1628 28

On the basis of the reported association between hepatitis B vaccination (HBvacc) and autoimmune demyelinating complications such as multiple sclerosis (MS), we have looked for aminoacid similarities between the small hepatitis B virus surface antigen (SHBsAg), and the MS-autoantigens myelin basic protein (MBP) and myelin oligodendrocyte glycoprotein (MOG) that could serve as targets of immunological cross-reactivity. Twenty-mer peptides spanning 4 SHBsAg/MOG and 1 SHBsAg/MBP mimicking pairs, were constructed and tested by ELISA as targets of cross-reactive responses. A total of 147 samples from 58 adults were collected before HBvacc (58/58), and post-HBvacc (48/58 before the second and 41/58 before the third boost). Eighty-seven sera from anti-SHBsAg antibody negative patients with various diseases were tested as pathological controls. Reactivity to at least one of the SHBsAg peptides was found in 8 (14%) pre-HBvacc subjects; amongst the remaining 50, reactivity to at least one of the SHBsAg peptides appeared in 47 (94%) post-HBvacc. Reactivity to at least one of the MOG mimics was present in 4 (8%) pre-HBvacc and in 30 (60%) post-HBvacc (p < 0.001). Overall 30/50 (60%) vaccinees had SHBsAg/MOG double reactivity on at least one occasion compared to none before-vaccination and in 2 (2%) of the pathological controls (p < 0.001 for both). SHBsAg/MOG double reactivity was cross-reactive as confirmed by inhibition studies. At 6 months post-vaccination, 3 of the 4 anti-MOG reactive cases before vaccination and 7 of the 24 (29%) of the anti-MOG reactive cases at 3 months post-vaccination had lost their reactivity to MOG5-24. There was no reactivity to the SHBsAg/MBP mimics. None of the vaccinees reported symptoms of demyelinating disorders. In view of the observed SHBsAg/MOG cross-reactivity, the vaccine's possible role as an immunomodulator of viral/self cross-reactivity must be further investigated.
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PMID:A study of molecular mimicry and immunological cross-reactivity between hepatitis B surface antigen and myelin mimics. 1629 28

Safety of vaccines must be excellent to make vaccine's strategy acceptable, since it usually has a deferred individual benefit but immediate adverse drug reactions (ADRs). Pharmacovigilance of vaccines after their marketing is crucial because, prior to its availability on the market, the size of clinical trials is insufficient to identify rare or deferred adverse effects. The Pharmacovigilance is based on "spontaneous reporting" of ADRs to the Pharmacovigilance Regional Centre (PVRC) which establishes a relationship between each drug taken by the patient and the ADRs occurrence (imputability). This method is crucial to generate alerts, but under-estimates the real frequency of ADRs (1 to 10% of severe ADRs are reported). Thus pharmacoepidemiology studies are necessary to confirm the alerts identified by spontaneous reporting. ADRs can be specific, related to the antigen of an attenuated alive virus vaccine (lymphocyte meningitis after anti-mumps vaccine) or non-specific, related to a component different from the antigen (aluminium hydroxide involved in the "macrophagic myofasciitis", allergic reactions to neomycin, latex, egg or gelatine). Importance of Pharmacovigilance of vaccines is illustrated. Data, especially case-control studies, about the relationship between multiple sclerosis and hepatitis B vaccine are summarised. Data about the relationship between Crohn's disease or autism and MMR vaccine are analysed. As vaccines are used in healthy people, their safety must be excellent to be accepted. To monitor them after their marketing is the unique way to detect rare ADRs. This surveillance is made through reporting of ADRs to the PVRC. However, an active and intensive surveillance of ADRs as the one set up from the marketing of Prevenar should be systematic.
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PMID:[Pharmacovigilance of vaccines]. 1634 70

Hepatitis B vaccines are highly effective and safe and have been incorporated into national immunization programs in over 150 countries. The major humoral immune response is to the common a determinant of the surface antigen protein of the virus. Approximately 5-10% of healthy immunocompetent subjects do not mount an antibody response (anti-HBs). Non-response is associated with different HLA-DR alleles and impaired Th cell response, among other factors such as route of injection, age, gender, body mass, and other factors. Important hepatitis B surface antigen variants have also been identified, which may have a potential impact on immunization and routine screening of blood, blood products and tissues, and organs for transplantation. Strategies for hepatitis B immunization are reviewed. Over 1,000 million doses of hepatitis B vaccine have been used with an outstanding record of safety. There is no evidence of an association between hepatitis B vaccines and the sudden infant death syndrome, chronic fatigue syndrome, and multiple sclerosis (MS). Several studies are in progress on treatment of chronic hepatitis B infection by immunization with multiple antigenic components, combination of vaccine with antiviral drugs and cytokines, T cell vaccines, DNA vaccines alone or with DNA encoded immunomodulatory cytokines, and direct genetic manipulation of antigen presenting cells.
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PMID:Protective efficacy, immunotherapeutic potential, and safety of hepatitis B vaccines. 1637 85


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