Hepatitis B vaccine and risk of multiple sclerosis

The impact of human vaccines on bacterial antimicrobial resistance. A review

At present, the dramatic rise in antimicrobial resistance (AMR) among important human bacterial pathogens is reaching a state of global crisis threatening a return to the pre-antibiotic era. AMR, already a significant burden on public health and economies, is anticipated to grow even more severe in the coming decades. Several licensed vaccines, targeting both bacterial (Haemophilus influenzae type b, Streptococcus pneumoniae, Salmonella enterica serovar Typhi) and viral (influenza virus, rotavirus) human pathogens, have already proven their anti-AMR benefits by reducing unwarranted antibiotic consumption and antibiotic-resistant bacterial strains and by promoting herd immunity. A number of new investigational vaccines, with a potential to reduce the spread of multidrug-resistant bacterial pathogens, are also in various stages of clinical development. Nevertheless, vaccines as a tool to combat AMR remain underappreciated and unfortunately underutilized. Global mobilization of public health and industry resources is key to maximizing the use of licensed vaccines, and the development of new prophylactic vaccines could have a profound impact on reducing AMR.

Do Vaccines Have a Role as a Cause of Autoimmune Neurological Syndromes?

Vaccines are the most important preventive measure against infectious diseases presently available. Although they have led to the eradication or the elimination of some infectious diseases, concerns about safety are among the main reasons for vaccine hesitancy. In some cases, the biological plausibility of a given damage in association with the temporal association between vaccine administration and disease development makes it difficult to define causality and can justify hesitancy. Only well-conducted epidemiological studies with adequate evaluation of results can clarify whether a true association between vaccines and adverse event development truly exists. Autoimmune neurological syndromes that follow vaccine use are among these. In this narrative review, the potential association between vaccines and the development of these syndromes are discussed. Literature analysis showed that most of the associations between vaccines and nervous system autoimmune syndromes that have been reported as severe adverse events following immunization are no longer evidenced when well-conducted epidemiological studies are carried out. Although the rarity of autoimmune diseases makes it difficult to strictly exclude that, albeit exceptionally, some vaccines may induce an autoimmune neurological disease, no definitive demonstration of a potential role of vaccines in causing autoimmune neurological syndromes is presently available. Consequently, the fear of neurological autoimmune disease cannot limit the use of the most important preventive measure presently available against infectious diseases.

Vaccination in patients under monoclonal antibody treatment: an updated comprehensive review

INTRODUCTION

Monoclonal antibodies (mAbs) have become an increasing source of biological treatments. Clinicians should make an effort to update their knowledge on mechanisms of action, indications, and adverse events of these novel therapies. Most of them have immunosuppressive effects and, therefore, vaccination is indicated.

AREAS COVERED

vaccination of patients under mAbs therapies.

EXPERT OPINION

Recommendations on vaccination are still based on expert recommendations and have not been updated in recent years. Specific recommendations for each mAb have not been addressed in the current literature. The aim of this comprehensive review was to collect all the therapeutic mAbs approved up to 1 January 2020 and, based on previous recommendations and the pharmaceutical characteristics of each drug, to propose an updated guide with recommendations on vaccination. Influenza, sequential pneumococcal and Hepatitis B vaccination in patients with negative serology were the only consistent recommendations. Hepatitis A vaccination was proposed for mAbs with special hepatotoxic characteristics. Other vaccines are reviewed and discussed. Several non-immunosuppressive mAbs were detected and, therefore, vaccinations not recommended. We hope that this review can serve as a starting point for compiling updated vaccination recommendations and collecting all the therapeutic mAbs approved up to 2020.

Vaccines and multiple sclerosis: a systematic review

Vaccinations are often the most effective tool against some disease known to mankind. This study offers a literature review on the role of vaccines regarding the risk of developing multiple sclerosis (MS) and MS relapse. The method used in this study is a systematic literature review on the database PubMed. The study found no change in risk of developing multiple sclerosis (MS) after vaccination against hepatitis B virus, human papillomavirus, seasonal influenza, measles-mumps-rubella, variola, tetanus, Bacillus Calmette-Guérin (BCG), polio, or diphtheria. No change in risk of relapse was found for influenza. Further research is needed for the potential therapeutic use of the BCG vaccine in patients in risk of developing MS and for the preventive potential of the tetanus and diphtheria vaccine.

Acute Demyelinating Events Following Vaccines: A Case-Centered Analysis

BACKGROUND

 Case reports have suggested that vaccines may trigger transverse myelitis (TM) or acute disseminated encephalomyelitis (ADEM), but the evidence for a causal association is inconclusive. We analyzed the association of immunization and subsequent development of TM or ADEM.

METHODS

 We identified all cases of TM and ADEM in the Vaccine Safety Datalink population. Using a case-centered method, we compared vaccination of each case to vaccination of all matched persons in the study population, who received the same type of vaccine, with respect to whether or not their vaccination occurred during a predetermined exposure interval. We calculated a risk difference (excess risk) of TM and ADEM for each vaccine.

RESULTS

 Following nearly 64 million vaccine doses, only 7 cases of TM and 8 cases of ADEM were vaccinated during the primary exposure window 5-28 days prior to onset. For TM, there was no statistically significant increased risk of immunization. For ADEM, there was no statistically significant increased risk following any vaccine except for Tdap (adolescent and adult tetanus, reduced diphtheria, acellular pertussis) vaccine. Based on 2 exposed cases, the odds ratio for Tdap exposure 5-28 days prior to ADEM onset was 15.8 (95% confidence interval [CI], 1.2-471.6; P = .04), and the estimated excess risk was 0.385 (95% CI, -.04 to 1.16) cases per million doses.

CONCLUSIONS

 We found no association between TM and prior immunization. There was a possible association of ADEM with Tdap vaccine, but the excess risk is not likely to be more than 1.16 cases of ADEM per million vaccines administered.

Monitoring product safety in the postmarketing environment

The safety profile of a medicinal product may change in the postmarketing environment. Safety issues not identified in clinical development may be seen and need to be evaluated. Methods of evaluating spontaneous adverse experience reports and identifying new safety risks include a review of individual reports, a review of a frequency distribution of a list of the adverse experiences, the development and analysis of a case series, and various ways of examining the database for signals of disproportionality, which may suggest a possible association. Regulatory agencies monitor product safety through a variety of mechanisms including signal detection of the adverse experience safety reports in databases and by requiring and monitoring risk management plans, periodic safety update reports and postauthorization safety studies. The United States Food and Drug Administration is working with public, academic and private entities to develop methods for using large electronic databases to actively monitor product safety. Important identified risks will have to be evaluated through observational studies and registries.

Barriers to the vaccination of children and adolescents and possible solutions

The benefits of vaccination are clearly demonstrated by the eradication or enormous decline in the incidence of many vaccine-preventable diseases, but the coverage of many highly recommended vaccines is still frequently inadequate and children continue to suffer from diseases that could have been prevented. The main aim of this paper is to discuss the recognized barriers to the vaccination of children and adolescents confronting national health systems, providers and parents, and the ways in which they can be overcome. Most of the problems underlying limited vaccination coverage among children are due to a lack of understanding on the part of healthcare providers and parents, which underlines the need for educational programmes specifically addressed to each of these groups. It is also essential that all of the physicians providing immunization develop approaches that acknowledge parents' concerns and respectfully try to correct any misinformation. Other means of extending vaccine coverage include the implementation of adequate systems for recording vaccine administration and the activation of effective reminder/recall systems, the provision of immunization services in some medical care specialties or by integrating healthcare sites, and the elimination or reduction of all the problems that currently limit access to vaccination services. However, it will take the combined efforts of healthcare systems and providers to pull down all of the barriers.

Ethics of mandatory vaccination for healthcare workers

Healthcare workers (HCWs) are at increased risk of contracting infections at work and further transmitting them to colleagues and patients. Immune HCWs would be protected themselves and act as a barrier against the spread of infections and maintain healthcare delivery during outbreaks, but vaccine uptake rates in HCWs have often been low. In order to achieve adequate immunisation rates in HCWs, mandatory vaccination policies are occasionally implemented by healthcare authorities, but such policies have raised considerable controversy. Here we review the background of this debate, analyse arguments for and against mandatory vaccination policies, and consider the principles and virtues of clinical, professional, institutional and public health ethics. We conclude that there is a moral imperative for HCWs to be immune and for healthcare institutions to ensure HCW vaccination, in particular for those working in settings with high-risk groups of patients. If voluntary uptake of vaccination by HCWs is not optimal, patients’ welfare, public health and also the HCW’s own health interests should outweigh concerns about individual autonomy: fair mandatory vaccination policies for HCWs might be acceptable. Differences in diseases, patient and HCW groups at risk and available vaccines should be taken into consideration when adopting the optimal policy.

Disease-specific adverse events following nonlive vaccines: a paradoxical placebo effect or a nocebo phenomenon?

Vaccines can cause adverse reactions (AR), i.e. adverse events following immunization (AEFIs) due to the vaccine, such as local reactions or fever. In addition, live attenuated vaccines which replicate in vaccinees can cause disease-specific AR, e.g. measles-like rash following measles vaccination. However, nonlive vaccines because they are inactivated and they do not replicate in vaccinees, are not likely to cause disease-specific AR. The aim of the study was to assess whether safety signals could be generated by an undescribed bias in spontaneous reporting of disease-specific AEFIs with nonlive vaccines. All AEFIs of Sanofi Pasteur MSD vaccines spontaneously reported in France from January 2000 to June 2010, coded according to MedDRA terms and collected in the company's pharmacovigilance database were analyzed. Vaccine-event pairs of interest were selected a priori. The disproportionality reporting rate methodology was used, comparing the proportion of a given event reported following a given vaccine to its proportion reported following all other studied vaccines. The Reporting Odds Ratio (ROR) was used for signals detection for each vaccine-event pair selected. A total of 33,275 AEFIs were analyzed. The calculated ROR showed a statistically disproportionate reporting rate and generated false safety signals for almost all the pairs tested. Three nonlive vaccine pairs were striking: gynaecological symptoms and the quadrivalent human papillomavirus (qHPV) vaccine; trismus and tetanus vaccines; hepatobiliary disorders and hepatitis B vaccines. In conclusion we have identified a new vaccine AE spontaneous reporting bias: "disease-specific adverse events following nonlive vaccines", showing that vaccinees and healthcare professionals tend to report preferentially the symptoms of the disease against which the nonlive vaccine was administered. We suggest that bias is subordinate to a paradoxical placebo effect and/or a nocebo phenomenon.

Human papillomavirus vaccine safety in Australia: experience to date and issues for surveillance

Australia was one of the first countries to licence a quadrivalent human papillomavirus (HPV) vaccine, rapidly followed by a federally funded program of universal vaccination of a broad age group of females through schools (12 to 18 years) and primary care (19 to 26 years). As of August 2009, more than 5.8 million doses of Gardasil((R)) (quadrivalent; Merck, New Jersey, USA) have been distributed in Australia and a total of 1394 suspected adverse events following immunisation (AEFI) have been reported to the passive surveillance system. Most reports are of common and expected reactions. Case series of more uncommon and serious AEFI, both known to be potentially vaccine related (anaphylaxis, conversion disorders and lipoatrophy) and otherwise (multiple sclerosis and pancreatitis) have been published.

[Vaccination and multiple sclerosis]

Vaccinations to prevent communicable diseases are, like in other chronic diseases, of special importance in patients with multiple sclerosis (MS). Various bacterial and viral infections have been shown to induce relapses of MS. Reports of possible adverse effects of vaccinations on the course of multiple sclerosis have led patients and treating physicians to exercise caution in the use of vaccines. A number of vaccines have been studied with respect to the risk in MS patients. Some vaccines, for example against yellow fever, are not indicated in MS due to the risk of MS exacerbation. In contrast, tetanus or hepatitis B vaccines do not represent a risk for manifestation or disease progression of MS. Before and during immunomodulatory therapy of MS special attention should be given to adequate protection against vaccine preventable diseases.This paper reviews the indications and specific side effects of vaccinations in MS patients. Additionally, issues of vaccination under immunomodulatory therapy of MS are discussed.

Acute encephalomyelitis associated with acute viral hepatitis type B

We describe the case of a 36-year-old woman who developed acute encephalo-myelitis after acute viral hepatitis type B. She was admitted to the hospital with a history of general malaise and nausea of 5 days duration. Her serum showed high transaminase levels and positive HBs-Ag and increased IgM HBc-Ab titers. She had urinary dysfunction, myoclonus and postural tremor of her extremities. Several days later, she developed bilateral limb ataxia and alteration of consciousness. The cerebrospinal fluid examinations showed pleocytosis and increased protein. Treatment with high-dose methylprednisolone resulted in a marked improvement of the clinical and CSF examination. Magnetic resonance imaging of the brain and the spinal cord did not disclose abnormal lesions. The symptoms and clinical course were quite similar to those of acute disseminated encephalomyelitis.

Human papilloma virus immunization in adolescent and young adults: a cohort study to illustrate what events might be mistaken for adverse reactions

BACKGROUND

The large-scale implementation of human papilloma virus (HPV) immunization will be followed by cases of autoimmune diseases occurring in temporal association with immunizations. To anticipate events that might be mistakenly assumed to be caused by immunization, their prevalence was monitored before vaccine introduction.

METHOD

Cohort study carried out within a database of female adolescents (n = 214,896) and young adults (n = 221,472) followed in the pre-HPV vaccine era (2005), computing rates of emergency consultations, hospitalizations and outpatient consultations, and estimation of risks of coincident associations.

RESULTS

Immune-mediated conditions were a frequent cause (10.3%) of emergency room consultation by adolescent girls. Nonallergic immune-mediated conditions affected 86 per 100,000, diabetes ranking first. In 2005, 53 per 100,000 adolescents and 389 per 100,000 women were hospitalized for diseases of presumed autoimmune origin, thyroiditis being the most frequent diagnosis. If HPV immunization had been used with 80% coverage, 3 per 100,000 adolescents would have required emergency care for asthma/allergy within 24 hours and 2 per 100,000 for diabetes within 1 week of an injection. The risks of hospitalization in temporal association with immunization are 4 times higher for thyroiditis than for multiple sclerosis or Guillain-Barré's syndrome, and more than 20 times higher in young women than in adolescents.

CONCLUSION

The distinction between HPV vaccine-caused adverse reactions and events only observed by chance in temporal association is difficult. The prior use of population-based data allows for identification of issues of potential concern, for monitoring the impact of large-scale interventions and for addressing rapidly vaccine-safety issues that may compromise vaccine programs.

Should hepatitis B vaccine be used for infants?

Chronic hepatitis B virus infection causes nearly all the deaths from this virus. As the initial infection occurs without symptoms and decades prior to the onset of cirrhosis and liver cancer, these consequences are rarely recognized as being caused by the virus. Consequently, its public health importance is under-recognized. Safe and effective vaccines have now been available for over 20 years. Concerns have been raised regarding the mercury preservative in vaccines leading to potential toxicity. But the evidence to date does not support any association of hepatitis B vaccine with serious adverse consequences. Protecting infants through immunization is the most effective control strategy. By 2005, over 80% of countries had implemented routine infant immunization. In countries with relatively low rates of hepatitis B virus infection, some have argued to defer immunization until later life. However, these arguments focus on the more visible acute infection. The possible future cost from a single infant infection argues for universal infant hepatitis B immunization--given the very high costs of treating its consequences (e.g., liver transplant) and the very low price of the vaccine.

An internet-based survey on parental attitudes towards immunization

Parental misperceptions have been identified as major barriers towards immunizations in children. By use of a German internet vaccine forum for lay persons, a survey was performed to assess current attitudes of parents regarding prevalent issues related to childhood vaccination. Of 6025 participants, 5722 (95.0%) regarded their paediatrician as the most important source of information regarding immunization, followed by leaflets (48.0%), health magazines (44.7%), and the internet (38.7%). Of currently generally recommended childhood immunizations, those against pertussis, Hib and especially measles-mumps-rubella were considered least important by parents. Furthermore, 22.6% of survey participants felt that immunizations are administered "too early" in life and 21.0 and 12.2% thought that overload of the child's immune system and induction of allergies, respectively, would be side effects of immunizations. This survey provided information on prevalent parental attitudes towards immunization, which should be used to plan information strategies to counteract existing misperceptions.