Hepatitis B vaccination and the putative risk of central demyelinating diseases – A systematic review and meta-analysis

The risk of acute disseminated encephalomyelitis (ADEM) following covid-19 vaccination in England: A self-controlled case-series analysis

Acute disseminated encephalomyelitis (ADEM) has been identified as an Adverse Event of Special Interest in the COVID-19 vaccine programme due to its long-standing temporal association with a wide range of other vaccines. Case reports of ADEM shortly following COVID-19 vaccination have now been documented.    There were 217 ADEM admissions in 215 individuals in the period 8th December 2020 to 31st March 2023. An increased risk of ADEM following the first dose of ChAdOx1 vaccine was observed (relative incidence (RI) = 3.13, 95% Confidence Interval (CI) [1.56-6.25]) with a vaccine attributable risk of 0.39 per million doses. When doses 1 and 2 were combined this increased risk remained just significant (1.96 [95%CI 1.01-3.82]). No significant increased risk was observed with any other vaccine or dose. This small, elevated risk after the first dose of ChAdOx1-S vaccine demonstrates how large national electronic datasets can be used to identify very rare risks and provides reassurance that any risk of ADEM following the ChAdOx1-S COVID-19 vaccination is extremely small. Given the rarity of this risk, further studies in settings with access to data on large populations should be carried out to verify these findings.

Efficacy and safety of hepatitis B vaccine: an umbrella review of meta-analyses

BACKGROUND

There is a lack of synthesis of literature to determine hepatitis B vaccine (HepB) strategies for hepatitis B virus (HBV) supported by quality evidence. We aimed to explore the efficacy and safety of HepB strategies among people with different characteristics.

RESEARCH DESIGN AND METHODS

PubMed, Cochrane Library, Embase, and Web of Science were searched for meta-analyses comparing the efficacy and safety of HepB up to July 2023.

RESULTS

Twenty-one meta-analyses comparing 83 associations were included, with 16 high quality, 4 moderate, and 1 low quality assessed by AMSTAR 2. Highly suggestive evidence supports HepB booster and HepB with 1018 adjuvant (HBsAg-1018) for improved seroprotection, and targeted and universal HepB vaccination reduced HBV infection Suggestive evidence indicated that targeted vaccination decreased the rate of hepatitis B surface antibody positivity and booster doses increased seroprotection in people aged 10-20. Weak evidence suggests potential local/systemic reaction risk with nucleotide analogs or HBsAg-1018. Convincing evidence shows HLA-DPB1*04:01 and DPB1*04:02 increased, while DPB1*05:01 decreased, hepatitis B antibody response. Obesity may reduce HepB seroprotection, as highly suggested.

CONCLUSION

Targeted vaccination could effectively reduce HBV infection, and adjuvant and booster vaccinations enhance seroprotection without significant reaction. Factors such as obesity and genetic polymorphisms may affect the efficacy.

Association between vaccination and the risk of central demyelination: results from a case-referent study

BACKGROUND

Few studies documented the potential association between vaccination and the risk of central demyelination (CD). Specifically, anti-hepatitis B and anti-human papillomavirus (HPV) vaccines have been the subject of distrust with regard to their implication to trigger CD.

METHODS

From a systematic national registry, patients with first signs of CD (cases) were identified and documented for their exposure to vaccination up to 24 months before the first signs occurred. This exposure was compared to that of a representative sample of general practice patients without a history of CD, randomly selected from a national registry (referents). CD cases were 2:1 matched on age, sex, index date (ID), and region of residence. Vaccines against influenza, HPV, hepatitis B and diphtheria-tetanus-pertussis-poliomyelitis-haemophilus (DTPPHae) were considered. Associations between vaccination and CD were assessed using multivariate conditional logistic regressions, controlled for confounding factors.

FINDINGS

564 CD cases were matched to 1,128 randomly selected referents (age range: 2-79 years old). Overall, 123 (22%) CD cases and 320 (28%) referents had received at least one vaccine within 24 months before ID. Adjusted odds ratios (ORs) for any vaccination were 0.69, 95% confidence interval (CI) [0.54-0.88] with respect to any CD first signs, 0.68 [0.51-0.90] for myelitis and 0.70 [0.42-1.17] for optic neuritis. Adjusted ORs for any CD first signs were 1.02 [0.71-1.47] for influenza vaccine (administered in 9.6% of cases and 10.4% of referents) and 0.72 [0.53-0.99] for DTPPHae vaccine (administered in 10.8% of cases and 14.5% of referents). Vaccines against hepatitis B and HPV were only administered in 1.1% and 1.2% of cases and in 2.9% and 3.2% of referents respectively, which statistically explained the point estimates < 1 (ORs of 0.39 [0.16-0.94] and of 0.32 [0.13-0.80]).

INTERPRETATION

No increased risk of CD incidence was observed amongst vaccinated patients. Lower rates of vaccination against hepatitis B and HPV observed in patients with CD compared to referents may be due to the reluctance of physicians to vaccinate patients considered at risk of CD.

International adaptation and validation of the Pro-VC-Be: measuring the psychosocial determinants of vaccine confidence in healthcare professionals in European countries

BACKGROUND

Healthcare professionals (HCPs) play an important role in vaccination; those with low confidence in vaccines are less likely to recommend them to their patients and to be vaccinated themselves. The study's purpose was to adapt and validate long- and short-form versions of the International Professionals' Vaccine Confidence and Behaviors (I-Pro-VC-Be) questionnaire to measure psychosocial determinants of HCPs' vaccine confidence and their associations with vaccination behaviors in European countries.

RESEARCH DESIGN AND METHODS

After the original French-language Pro-VC-Be was culturally adapted and translated, HCPs involved in vaccination (mainly GPs and pediatricians) across Germany, Finland, France, and Portugal completed a cross-sectional online survey in 2022. A 10-factor multigroup confirmatory factor analysis (MG-CFA) of the long-form (10 factors comprising 34 items) tested for measurement invariance across countries. Modified multiple Poisson regressions tested the criterion validity of both versions.

RESULTS

2,748 HCPs participated. The 10-factor structure fit was acceptable to good everywhere. The final MG-CFA model confirmed strong factorial invariance and showed very good fit. The long- and short-form I-Pro-VC-Be had good criterion validity with vaccination behaviors.

CONCLUSION

This study validates the I-Pro-VC-Be among HCPs in four European countries; including long- and short-form tools for use in research and public health.

Measuring psychosocial determinants of vaccination behavior in healthcare professionals: validation of the Pro-VC-Be short-form questionnaire

BACKGROUND

Vaccine confidence among health care professionals (HCPs) is a key determinant of vaccination behaviors. We validate a short-form version of the 31-item Pro-VC-Be (Health Professionals Vaccine Confidence and Behaviors) questionnaire that measures HCPs' confidence in and commitment to vaccination.

RESEARCH DESIGN AND METHODS

A cross-sectional survey among 2,696 HCPs established a long-form tool to measure 10 dimensions of psychosocial determinants of vaccination behaviors. Confirmatory factor analysis (CFA) models tested the construct validity of 69,984 combinations of items in a 10-item short form tool. The criterion validity of this tool was tested with four behavioral and attitudinal outcomes using weighted modified Poisson regressions. An immunization resource score was constructed from summing the responses of the dimensions that can influence HCPs' pro-vaccination behaviors: vaccine confidence, proactive efficacy, and trust in authorities.

RESULTS

The short-form tool showed good construct validity in CFA analyses (RMSEA = 0.035 [0.024; 0.045]; CFI = 0.956; TLI = 0.918; SRMR 0.027) and comparable criterion validity to the long-form tool. The immunization resource score showed excellent criterion validity.

CONCLUSIONS

The Pro-VC-Be short-form showed good construct validity and criterion validity similar to the long-form and can therefore be used to measure determinants of vaccination behaviors among HCPs.

Challenges and insights in immunization in patients with demyelinating diseases: a bench-to-bedside and evidence-based review

BACKGROUND

Infections are among the main causes of death in patients with demyelinating diseases of the central nervous system (CNSDD). Vaccines are effective methods in reducing hospitalization and death from infectious diseases, but they are challenging in patients with CNSDD because of autoimmunity and immunosuppression.

OBJECTIVES

To summarize the pathophysiological rationale and main evidence for vaccine recommendations in patients with CNSDD.

METHODS

Specialists with different backgrounds on the subject: a neurologist specialized in demyelinating diseases, an infectious diseases specialist and an immunologist, presented a critical narrative review of vaccination literature in patients with CNSDD, highlighting which vaccines should or should not be administered and the best time for it.

RESULTS

Patients with DDSNC are at increased risk of vaccine-preventable viral and bacterial infections. Vaccines can prevent herpes zoster, hepatitis B reactivation, HPV-associated warts and tumors, viral and bacterial pneumonia, and meningitis. Live attenuated virus vaccines should not be used when the patient is on immunosuppression. Vaccines should be avoided during relapses. The greatest vaccine efficacy is given before treatment or at the end of medication.

CONCLUSION

Patients with DDSNC need differentiated immunization in relation to additional vaccines, contraindicated vaccines and timing of vaccination.

Interpretation of vaccine associated neurological adverse events: a methodological and historical review

As a result of significant recent scientific investment, the range of vaccines available for COVID-19 prevention continues to expand and uptake is increasing globally. Although initial trial safety data have been generally reassuring, a number of adverse events, including vaccine induced thrombosis and thrombocytopenia (VITT), have come to light which have the potential to undermine the success of the vaccination program. However, it can be difficult to interpret available data and put these into context and to communicate this effectively. In this review, we discuss contemporary methodologies employed to investigate possible associations between vaccination and adverse neurological outcomes and why determining causality can be challenging. We demonstrate these issues by discussing relevant historical exemplars and explore the relevance for the current pandemic and vaccination program. We also discuss challenges in understanding and communicating such risks to clinicians and the general population within the context of the 'infodemic' facilitated by the Internet and other media.

Crisis of confidence in vaccination and the role of social media

INTRODUCTION

The aim of this paper is to review the current situation of vaccine hesitancy, with emphasis on children with neurological disorders, and to present the role social media plays in this situation.

METHODS

A literature review using the following search words was performed: vaccine∗ OR immune∗ AND hesitancy OR confidence AND social media.

RESULTS

The search retrieved 277 results; 17 duplicates and 234 irrelevant articles were excluded. 43 articles were fully analyzed.

CONCLUSIONS

An increasing number of parents are becoming vaccine hesitant. Their motives are complex and nuanced and involve factors related to vaccine safety and efficiency, perceived personal risks and benefits, socio-demographic and psychological characteristics. Attitudes toward vaccination differ in adolescents from their parents. In children with neurological disorders, factors involved in vaccination decision included physicians' knowledge of neurological diseases and parents' concerns that vaccination would exacerbate the chronic disorder. Unfortunately, the current pandemic is associated with an increase in vaccine hesitancy and brought forward unique determinants. The social media platforms can be a tool for the anti-vaccine movement to spread misinformation, but it can also be valued as a way for promoting health and pro-vaccine information.

Autoimmune phenomena following SARS-CoV-2 vaccination

Vaccines represent an attractive possible solution to the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic. Widespread vaccine distribution has yet to occur in most countries, partially due to public concerns regarding possible side effects. While studies indicate the vaccine is exceptionally safe, rare systemic side effects remain possible. In Israel, where a large percentage of the population has been rapidly vaccinated, such adverse events may be more apparent. We report a series of patients presenting with de-novo or flares of existing autoimmune conditions associated with the Pfizer BNT162b2 mRNA SARS-CoV-2 vaccine. All patients were assessed in our tertiary care center in Israel and had no history of previous SARS-COV-2 infection. We observed that while immune phenomena may occur following vaccination, they usually follow a mild course and require modest therapy. We briefly expound on the theoretical background of vaccine related autoimmunity and explore future research prospects.

Role of environmental factors in multiple sclerosis

INTRODUCTION

Environmental factors play a significant role in the pathogenesis and progression of multiple sclerosis (MS), either acting alone or by interacting with other environmental or genetic factors. This cumulative exposure to external risk factors is highly complex and highly variable between individuals.

AREAS COVERED

We narratively review the current evidence on the role of environment-specific risk factors in MS onset and progression, as well as the effect of gene-environment interactions and the timing of exposure We have reviewed the latest literature, by Ovid Medline, retrieving the most recently published systematic reviews and/or meta-analyses and more recent studies not previously included in meta-analyses or systematic reviews.

EXPERT OPINION

There is some good evidence supporting the impact of some environmental risk factors in increasing the risk of developing MS. Tobacco smoking, low vitamin D levels and/or low sun exposure, Epstein Barr Virus (EBV) seropositivity and a history of infectious mononucleosis may increase the risk of developing MS. Additionally, there is some evidence that gene-smoking, gene-EBV, and smoking-EBV interactions additively affect the risk of MS onset. However, the evidence for a role of other environmental factors in MS progression is limited. Finally, there is some evidence that tobacco smoking, insufficient vitamin D levels and/or sun exposure have impacts on MS phenotypes and various markers of disease activity including relapse, disability progression and MRI findings. Clearly the effect of environmental factors on MS disease course is an area that requires significantly more research.

Can Vaccination Trigger Autoimmune Disorders? A Meta-Analysis

Vaccination as an important tool in the fight against infections has been suggested as a possible trigger of autoimmunity over the last decades. To confirm or refute this assumption, a Meta-analysis of Autoimmune Disorders Association With Immunization (MADAWI) was conducted. Included in the meta-analysis were a total of 144 studies published in 1968–2019 that were available in six databases and identified by an extensive literature search conducted on 30 November 2019. The risk of bias classification of the studies was performed using the Newcastle–Ottawa Quality Assessment Scale. The strength of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation. While our primary analysis was conducted in terms of measures of association employed in studies with a low risk of bias, the robustness of the MADAWI outcome was tested using measures independent of each study risk of bias. Additionally, subgroup analyses were performed to determine the stability of the outcome. The pooled association of 0.99 (95% confidence interval, 0.97–1.02), based on a total of 364 published estimates, confirmed an equivalent occurrence of autoimmune disorders in vaccinated and unvaccinated persons. The same level of association reported by studies independently of the risk of bias was supported by a sufficient number of studies, and no serious limitation, inconsistency, indirectness, imprecision, and publication bias. A sensitivity analysis did not reveal any discrepancy in the primary result. Current common vaccination is not the cause of any of the examined autoimmune disorders in the medium and long terms.

HBV vaccine and risk of developing multiple sclerosis: a systematic review and meta-analysis

Hepatitis B virus (HBV) infection is one the most common in the world. Aim of this study is to perform a systematic review on the relationship between HBV vaccination and multiple sclerosis. Research was conducted on Pubmed, ISI Web of Science, and Scopus. Terms "hepatitis b vaccination" and "multiple sclerosis" were used. Meta-analysis and metaregression were performed. 414 papers were found. Seven articles were selected. For the reported crude risk estimates for MS no statistically significant association was observed with pooled OR 1,19 (95%CI: 0,96-1,49). For the adjusted ORs, the pooled odds ratio (OR) was 0, 965 (95%CI: 0,886- 1,051). Meta regression show that year of publication is negatively (β: -0,019; P < 0.001) and NOS score and publishing in Europe are positively associated with O.R. value. Funnel plot showed the presence of publication bias. Results showed that Hepatitis B vaccination is not associated with an increased risk of developing MS.

Immunization in multiple sclerosis and other childhood immune-mediated disorders of the central nervous system: A review of the literature

Childhood is a period where most vaccines are administered in order to build-up immunological memory, and immunization against vaccine-preventable diseases is an essential part of child care and health. The administration of vaccines to children with inflammatory diseases is a frequent point of concern for parents and physicians. Published information on the relation between vaccines and autoinflammatory diseases of the central nervous system (CNS) consists of case and cohort studies and reviews, in great majority on adult patients. Vaccines do not have any established causative or triggering effects on these diseases. Another issue is the immunization schedule of patients with autoinflammatory CNS diseases, specifically the interactions between the disorder, the clinical status, the treatment and the vaccine. In this review, we summarize the existing information between autoinflammatory disorders of the CNS and vaccines in childhood and underline the points to be considered under various treatment regimens.

[Hepatitis B vaccine and liver cancer]

Hepatitis B Virus (HBV) chronic infection contributes to a high risk of hepatocellular cancer (HCC) development. HBV is a strong cancer inducer, due to natural history of infection, virological characteristics and viral DNA integrations events in host genome. Prolonged infection and high viral loads, particularly frequent in patients infected in childhood, are risk factors of HCC development for patients with HBV chronic infection. A HBV vaccine, based on immunization against the surface protein HBs, showed a strong efficacy to prevent chronic HBV infection. The development of universal neonatal vaccination programmes contributed to the decrease of HBV chronic infection incidence in children of high endemic areas. Although HBs antibodies levels diminished years after vaccination, HBV neonatal vaccination programmes led to a lower incidence of chronic HBV infection among young adults. The decrease of HBV chronic infection incidence was associated to a reduction of HCC incidence in children and young adults from areas with a high prevalence of HBV infection.

Antiviral therapy for the sexually transmitted viruses: recent updates on vaccine development

INTRODUCTION

The sexually transmitted infections (STIs) caused by viruses including human T cell leukemia virus type-1 (HTLV-1), human immunodeficiency virus-1 (HIV-1), human simplex virus-2 (HSV-2), hepatitis C virus (HCV), hepatitis B virus (HBV), and human papillomavirus (HPV) are major public health issues. These infections can cause cancer or result in long-term health problems. Due to high prevalence of STIs, a safe and effective vaccine is required to overcome these fatal viruses.

AREAS COVERED

This review includes a comprehensive overview of the literatures relevant to vaccine development against the sexually transmitted viruses (STVs) using PubMed and Sciencedirect electronic search engines. Herein, we discuss the efforts directed toward development of effective vaccines using different laboratory animal models including mice, guinea pig or non-human primates in preclinical trials, and human in clinical trials with different phases.

EXPERT OPINION

There is no effective FDA approved vaccine against the sexually transmitted viruses (STVs) except for HBV and HPV as prophylactic vaccines. Many attempts are underway to develop vaccines against these viruses. There are several approaches for improving prophylactic or therapeutic vaccines such as heterologous prime/boost immunization, delivery system, administration route, adjuvants, etc. In this line, further studies can be helpful for understanding the immunobiology of STVs in human. Moreover, development of more relevant animal models is a worthy goal to induce effective immune responses in humans.

Hepatitis B vaccine development and implementation

Vaccination against hepatitis B is the most effective strategy to control HBV infection. The first licensed hepatitis B vaccine was developed by the purification of hepatitis B surface antigen (HBsAg) from plasma of asymptomatic HBsAg carriers. Then, the recombinant DNA technology enabled the development of recombinant hepatitis B vaccine. A series of three doses vaccine can elicit long-term protection more than 30 y. Concurrent use of hepatitis B immunoglobulin and hepatitis B vaccine has substantially reduced the mother-to-child transmission of HBV, nearly zero infection in children of carrier mother with negative hepatitis B e antigen (HBeAg) and 5-10% infection in children of HBeAg-positive mothers. By the end of 2018, 189 countries adopted universal hepatitis B vaccination program, which has dramatically reduced the global prevalence of HBsAg in children <5 y of age, from 4.7% in the prevaccine era to 1.3% in 2015. However, the implementation of universal hepatitis B vaccination in some regions is suboptimal and timely birth dose vaccine is not routinely administered in more than half of newborn infants. Optimal worldwide universal hepatitis B vaccination requires more efforts to overcome the social and economic challenges.

Vaccine Safety: Myths and Misinformation

The World Health Organization has named vaccine hesitancy as one of the top ten threats to global health in 2019. The reasons why people choose not to vaccinate are complex, but lack of confidence in vaccine safety, driven by concerns about adverse events, has been identified as one of the key factors. Healthcare workers, especially those in primary care, remain key influencers on vaccine decisions. It is important, therefore, that they be supported by having easy access to trusted, evidence-based information on vaccines. Although parents and patients have a number of concerns about vaccine safety, among the most common are fears that adjuvants like aluminum, preservatives like mercury, inactivating agents like formaldehyde, manufacturing residuals like human or animal DNA fragments, and simply the sheer number of vaccines might be overwhelming, weakening or perturbing the immune system. As a consequence, some fear that vaccines are causing autism, diabetes, developmental delays, hyperactivity, and attention-deficit disorders, amongst others. In this review we will address several of these topics and highlight the robust body of scientific evidence that refutes common concerns about vaccine safety.

Do Vaccines Trigger Neurological Diseases? Epidemiological Evaluation of Vaccination and Neurological Diseases Using Examples of Multiple Sclerosis, Guillain-Barré Syndrome and Narcolepsy

This article evaluates the epidemiological evidence for a relationship between vaccination and neurological disease, specifically multiple sclerosis, Guillain-Barré syndrome and narcolepsy. The statistical methods used to test vaccine safety hypotheses are described and the merits of different study designs evaluated; these include the cohort, case-control, case-coverage and the self-controlled case-series methods. For multiple sclerosis, the evidence does not support the hypothesized relationship with hepatitis B vaccine. For Guillain-Barré syndrome, the evidence suggests a small elevated risk after influenza vaccines, though considerably lower than after natural influenza infection, with no elevated risk after human papilloma virus vaccine. For narcolepsy, there is strong evidence of a causal association with one adjuvanted vaccine used in the 2009/10 influenza pandemic. Rapid investigation of vaccine safety concerns, however biologically implausible, is essential to maintain public and professional confidence in vaccination programmes.

Image of the new vaccination obligation through the media

INTRODUCTION

Vaccination campaigns always go hand by hand with controversies about their safety and usefulness. The widespread perception of vaccines as dangerous induces a decrease in the population immunization coverage, which led The French Ministry of Health to add 8 new mandatory vaccines to the 3 existing ones. The objective of this study is to analyze the information conveyed by the media and received by the French population about this new legislation.

METHOD

The newspaper articles and television and radio programs were selected from the media with the highest audience rate from January 2016 to May 2018. They were analyzed according to the grounded theory, up to data saturation, with double coding.

RESULTS

The qualitative analysis included 38 written press articles, 18 radio programs and 18 television programs. After coding, several themes emerged. Discussions about the usefulness of vaccination, trust in vaccines, vaccination coverage, and the cost of measure were controversial in the media. Questions about ethics were also mentioned. The description of anti-vaccines by journalists and some doctors conveyed a negative image while reminding their strong mobilization through social media. The law and its implementation details were frequently reminded across the different media.

DISCUSSION-CONCLUSION

Traditional media give opposing views on immunization obligations. Vaccination is supported by a majority of doctors. Parents share their fears and concerns about vaccination and its adverse effects. An effort regarding public communication seems necessary in order to reassure the population. The study of other media, such as the Internet, could help to deepen this study.

The effects of message framing and healthcare provider recommendation on adult hepatitis B vaccination: A randomized controlled trial

Many adults in the U.S. do not receive recommended vaccines, and the research literature remains inconclusive on the best communication strategies for increasing this behavior. This study examined the association of message framing (gained-framed vs. loss-framed vs. control), and healthcare provider (HCP) recommendation (offered vs. recommended) on uptake of adult hepatitis B virus (HBV) vaccination in a high risk population using a 3 × 2 block design randomized controlled trial. Fear of shots, fear of vaccines, and perceived message framing were examined in secondary analyses. Of the 1747 participants, 47.7% (n = 833) received 0 doses of HBV vaccine, 27.8% (n = 485) received 1 dose, 10.4% received 2 doses, and 14.1% received all 3 recommended doses. There was not a significant interaction between message framing and HCP recommendation (p = .59). Mean number of doses received by the gain-framed group (m = 0.96) was not significantly different from the loss-framed group (m = 0.97, RR = 0.99, 95% CI = 0.88-1.12). However, those receiving any framing message received significantly more doses (m = 0.96) than those in the control condition (m = 0.81, RR = 1.17, 95%CI = 1.06-1.31). Participants who received a HCP recommendation received significantly more vaccine doses (m = 0.95) than those in the vaccine-offered condition (mean = 0.82, RR = 1.16, 95%CI = 1.05-1.28). These results suggest there is no difference in vaccine uptake between gain-frame and loss-frame messages, but both are better than a control message. These results also support advising HCP to provide a strong recommendation for vaccinations beyond merely offering it to patients. This study has implications for vaccine uptake beyond HBV, and can inform future research on effective vaccine communication research. Clinicaltrials.gov Identifier: NCT00739752. Registration date: August 20, 2008.

Identifying the culprits in neurological autoimmune diseases

The target organ of neurological autoimmune diseases (NADs) is the central or peripheral nervous system. Multiple sclerosis (MS) is the most common NAD, whereas Guillain-Barré syndrome (GBS), myasthenia gravis (MG), and neuromyelitis optica (NMO) are less common NADs, but the incidence of these diseases has increased exponentially in the last few years. The identification of a specific culprit in NADs is challenging since a myriad of triggering factors interplay with each other to cause an autoimmune response. Among the factors that have been associated with NADs are genetic susceptibility, epigenetic mechanisms, and environmental factors such as infection, microbiota, vitamins, etc. This review focuses on the most studied culprits as well as the mechanisms used by these to trigger NADs.

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Neurological autoimmune diseases are caused by a complex interaction between genes, environmental factors, and epigenetic deregulation.

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Infectious agents can cause an autoimmune reaction to myelin epitopes through molecular mimicry and/or bystander activation.

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Gut microbiota dysbiosis contributes to neurological autoimmune diseases.

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Smoking increases the risk of NADs through inflammatory signaling pathways, oxidative stress, and Th17 differentiation.

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Deficiency in vitamin D favors NAD development through direct damage to the central and peripheral nervous system.