Guillain-Barré syndrome after Gardasil vaccination: data from Vaccine Adverse Event Reporting System 2006-2009

Incidence of Guillain-Barré syndrome in the world between 1985 and 2020: A systematic review

Introduction

Guillain-Barré syndrome (GBS) is an acute inflammatory demyelinating polyradiculoneuropathy that affects the peripheral nervous system. The study aimed to describe the incidence of GBS in the world up to the year 2020.

Methods

A systematic review was conducted. Searches were done in four databases, PUBMED, EMBASE, EBSCO and Biblioteca virtual em Saude (BVS), and in grey literature and manual search in the reference lists of eligible studies.

Results

A total of 72 studies were included. The incidence of GBS among the cohort studies varied from 0.30 to 6.08 cases per 100.000 habitants and 0.42 to 6.58 cases per 100.000 person-years. Among the self-controlled studies, the risk incidence ranged from 0.072 to 1 case per 100.000 habitants and 1.73 to 4.30 cases per 100.000 person-years.

Conclusions

The reported incidence of GBS in the world among the studies included in the review is slightly higher than that reported in previous studies. The highest incidence rates were associated with public health events of international concern.

Adverse events from HPV vaccination in Taiwan

The safety of human papillomavirus (HPV) vaccines has been evaluated continuously in pre-licensure clinical trials, post-marketing surveillance systems, and observational studies. Most studies have found no significant association between serious adverse events and HPV vaccination. However, these studies have focused on Western populations; similar studies focusing on Asian populations are insufficient. Our retrospective cohort study used the HPV-vaccination records of junior high-school adolescent girls aged 12-15 years between 2013 and 2018 in Taiwan's National Immunization Information System and linked them to a registry for beneficiaries in Taiwan's National Health Insurance Database (NHID) to establish the vaccinated group. We selected 19 serious diseases as serious adverse events. We compared the incidence rates of these serious adverse events between the vaccinated group and girls in the same age group population, and we calculated the standardized incidence ratio (SIR) to evaluate the risk of serious adverse events after HPV vaccination. Because of the onset of different types of diseases, we set three periods after the subjects received HPV vaccination: within 3 months, within 1 year, and during the study period (2013-2018). The results showed the incidence rates and the SIRs of 19 selected adverse events. Among the 19 selected serious adverse events, the disease with the highest incidence rate during the study period was fibromyalgia (73.23 cases per million population), and the disease with the lowest incidence rate during the study period was Crohn's disease (0.15 cases per million population). The results showed no statistically significant increases in the risk of 19 selected serious adverse events and indicated no association between HPV vaccination and serious adverse events. Given the benefits and safety of HPV vaccination, our research can reduce concerns about vaccine side effects, inform health policies and improve public and clinician's acceptance of HPV vaccine policy.

COVID-19 as a trigger of Guillain-Barré syndrome: A review of the molecular mechanism

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused a pandemic with serious complications. After coronavirus disease 2019 (COVID-19), several post-acute COVID-19 syndromes (PACSs) and long-COVID sequels were reported. PACSs involve many organs, including the nervous, gustatory, and immune systems. One of the PACSs after SARS-CoV-2 infection and vaccination is Guillain-Barré syndrome (GBS). The incidence rate of GBS after SARS-CoV-2 infection or vaccination is low. However, the high prevalence of COVID-19 and severe complications of GBS, for example, autonomic dysfunction and respiratory failure, highlight the importance of post-COVID-19 GBS. It is while patients with simultaneous COVID-19 and GBS seem to have higher admission rates to the intensive care unit, and demyelination is more aggressive in post-COVID-19 GBS patients. SARS-CoV-2 can trigger GBS via several pathways like direct neurotropism and neurovirulence, microvascular dysfunction and oxidative stress, immune system disruption, molecular mimicry, and autoantibody production. Although there are few molecular studies on the molecular and cellular mechanisms of GBS occurrence after SARS-CoV-2 infection and vaccination, we aimed to discuss the possible pathomechanism of post-COVID-19 GBS by gathering the most recent molecular evidence.

Experimental Validation of MHC Class I and II Peptide-Based Potential Vaccine Candidates for Human Papilloma Virus Using Sprague-Dawly Models

Human papilloma virus (HPV) causes cervical and many other cancers. Recent trend in vaccine design is shifted toward epitope-based developments that are more specific, safe, and easy to produce. In this study, we predicted eight immunogenic peptides of CD4+ and CD8+ T-lymphocytes (MHC class I and II as M1 and M2) including early proteins (E2 and E6), major (L1) and minor capsid protein (L2). Male and female Sprague Dawly rats in groups were immunized with each synthetic peptide. L1M1, L1M2, L2M1, and L2M2 induced significant immunogenic response compared to E2M1, E2M2, E6M1 and E6M2. We observed optimal titer of IgG antibodies (>1.25 g/L), interferon-γ (>64 ng/L), and granzyme-B (>40 pg/mL) compared to control at second booster dose (240 µg/500 µL). The induction of peptide-specific IgG antibodies in immunized rats indicates the T-cell dependent B-lymphocyte activation. A substantial CD4+ and CD8+ cell count was observed at 240 µg/500 µL. In male and female rats, CD8+ cell count for L1 and L2 peptide is 3000 and 3118, and CD4+ is 3369 and 3484 respectively compared to control. In conclusion, we demonstrated that L1M1, L1M2, L2M1, L2M2 are likely to contain potential epitopes for induction of immune responses supporting the feasibility of peptide-based vaccine development for HPV.

A review of the potential neurological adverse events of COVID-19 vaccines

Despite the advantages of getting access to the coronavirus disease 2019 (COVID-19) vaccines, their potential ability to induce severe adverse events (AEs) has been a significant concern. Neurological complications are significant among the various adverse events following immunization (AEFI) due to their likely durability and debilitating sequelae. Neurological AEs following COVID-19 vaccination can either exacerbate or induce new-onset neuro-immunologic diseases, such as myasthenia gravis (MG) and Guillain-Barre syndrome (GBS). The more severe spectrum of AEs post-COVID19 vaccines has included seizures, reactivation of the varicella-zoster virus, strokes, GBS, Bell's palsy, transverse myelitis (TM), and acute disseminated encephalomyelitis (ADEM). Here, we discuss each of these neurological adverse effects separately.

Toward Establishing an Ideal Adjuvant for Non-Inflammatory Immune Enhancement

The vertebrate immune system functions to eliminate invading foreign nucleic acids and foreign proteins from infectious diseases and malignant tumors. Because pathogens and cancer cells have unique amino acid sequences and motifs (e.g., microbe-associated molecular patterns, MAMPs) that are recognized as "non-self" to the host, immune enhancement is one strategy to eliminate invading cells. MAMPs contain nucleic acids specific or characteristic of the microbe and are potential candidates for immunostimulants or adjuvants. Adjuvants are included in many vaccines and are a way to boost immunity by deliberately administering them along with antigens. Although adjuvants are an important component of vaccines, it is difficult to evaluate their efficacy ex vivo and in vivo on their own (without antigens). In addition, inflammation induced by currently candidate adjuvants may cause adverse events, which is a hurdle to their approval as drugs. In addition, the lack of guidelines for evaluating the safety and efficacy of adjuvants in drug discovery research also makes regulatory approval difficult. Viral double-stranded (ds) RNA mimics have been reported as potent adjuvants, but the safety barrier remains unresolved. Here we present ARNAX, a noninflammatory nucleic acid adjuvant that selectively targets Toll-like receptor 3 (TLR3) in antigen-presenting dendritic cells (APCs) to safely induce antigen cross-presentation and subsequently induce an acquired immune response independent of inflammation. This review discusses the challenges faced in the clinical development of novel adjuvants.

No significant increase in Guillain-Barré syndrome after COVID-19 vaccination in adults: A vaccine adverse event reporting system study

Objective

To investigate the association between Guillain-Barré syndrome (GBS) and COVID-19 vaccination.

Background

On July 13, 2021, the US Food and Drug Administration (FDA) released a new warning that Johnson & Johnson COVID-19 vaccine could increase the risk of developing GBS.

Methods

The reporting rate of adult GBS after COVID-19 vaccination, ascertained with Brighton criteria, was compared with the reporting rate after other vaccinations during the same time period, and also compared with the reporting rate during control periods. Statistical methods such as proportion tests, and Pearson’s chi-squared test were utilized to identify significant relationships. Self-controlled and case centered analyses were conducted. A machine learning model was utilized to identify the factors associated with a worse outcome defined as emergency room (ER) or doctor visits, hospitalizations, and deaths.

Results

The reporting rate of GBS after COVID-19 vaccination was significantly higher than after influenza and other vaccinations (49.7, 0.19, 0.16 per 10 million, p < 0.0001). However, the reporting rate was within the incidence range of GBS in the general population. Using self-controlled and case centered analyses, there was a significant difference in the reporting rate of GBS after COVID-19 vaccination between the risk period and control period (p < 0.0001). There was an estimated 0.7–1.7 per million excess reports of GBS within 6 weeks of COVID-19 vaccination. Machine learning model demonstrated that female gender and age between 18 and 44 are associated with worse outcome. No association was found between the onset interval of GBS and its prognosis.

Conclusions

Although the reporting rate of GBS after COVID-19 vaccination was not statistically different than that of the general population, the increased reporting of GBS within the first 6 weeks after COVID-19 vaccination, more so than with other vaccinations, suggests that some cases of GBS are temporally associated with COVID-19 vaccination. However, there is a reduction in the reporting rate of GBS after other vaccines, compared to reporting rates pre-COVID-19, highlighting limitations inherent in any passive surveillance system. These findings warrant continuous analysis of GBS after COVID-19 vaccination. Further improvement of the machine learning model is needed for clinical use.

Population-Based Incidence of Guillain-Barré Syndrome During Mass Immunization With Viral Vaccines: A Pooled Analysis

Misunderstanding temporal coincidence of adverse events during mass vaccination and invalid assessment of possible safety concerns have negative effects on immunization programs, leading to low immunization coverage. We conducted this systematic review and meta-analysis to identify the incidence rates of GBS that are temporally associated with viral vaccine administration but might not be attributable to the vaccines. By literature search in Embase and PubMed, we included 48 publications and 2,110,441,600 participants. The pooled incidence rate of GBS was 3.09 per million persons (95% confidence interval [CI]: 2.67 to 3.51) within six weeks of vaccination, equally 2.47 per 100,000 person-year (95%CI: 2.14 to 2.81). Subgroup analyses illustrated that the pooled rates were 2.77 per million persons (95%CI: 2.47 to 3.07) for individuals who received the influenza vaccine and 2.44 per million persons (95%CI: 0.97 to 3.91) for human papillomavirus (HPV) vaccines, respectively. Our findings evidence the GBS-associated safety of virus vaccines. We present a reference for the evaluation of post-vaccination GBS rates in mass immunization campaigns, including the SARS-CoV-2 vaccine.

Risk of Guillain-Barré syndrome after vaccination against human papillomavirus: a systematic review and meta-analysis, 1 January 2000 to 4 April 2020

BackgroundGuillain-Barré syndrome (GBS) is a rare autoimmune disease that can follow viral infections and has in a few cases been linked to vaccinations. Pre-licensure clinical trials did not observe an association between human papillomavirus (HPV) vaccination and GBS, a post-marketing study from 2017 reported an increased relative risk.AimWe assessed the risk of GBS after HPV vaccination through a systematic literature review and meta-analysis.MethodsWe searched Embase, MEDLINE and Cochrane for studies reporting on the risk of GBS after HPV vaccination in individuals aged ≥ 9 years, published between 1 January 2000 and 4 April 2020, excluding studies without a comparator group. Seven studies reporting relative effect sizes were pooled using random-effects meta-analysis. We assessed quality of evidence using the GRADE approach. Study protocol was registered (PROSPERO No. #CRD42019123533).ResultsOf 602 identified records, we included 25 studies. Based on over 10 million reports, cases of GBS were rare. In 22 studies no increased risk was observed, while in three studies a signal of increased risk of GBS after HPV vaccination was identified. Meta-analysis yielded a pooled random-effects ratio of 1.21 (95% CI: 0.60-2.43); I2 = 72% (95% CI: 36-88). This translates to a number needed to harm of one million to be vaccinated to generate one GBS case. Quality of evidence was very low.ConclusionsThe absolute and relative risk of GBS after HPV vaccination is very low and lacks statistical significance. This is reassuring for the already implemented vaccination programmes and should be used in respective communication activities.

Guillain-Barré syndrome following the first dose of Pfizer-BioNTech COVID-19 vaccine: case report and review of reported cases

Background

Since the SARS-CoV-2 pandemic has started in December 2019, millions of people have been infected all over the world. Vaccination is the most efficient tool to end this pandemic, but vaccine surveillance is necessary to identify side effects. Some studies have shown that neurological complications after COVID-19 vaccination are rare and dominated by demyelinating disease.

Case presentation

We present a case of a 67-year-old man who presented 7 days following his first dose of Pfizer-BioNTech COVID-19 vaccine a rapidly progressive ascending muscle weakness. The diagnosis of Guillain-Barré syndrome (GBS) was confirmed according to the clinical features, the albumino-cytological dissociation in the cerebrospinal fluid, and the electroneuromyography findings. The workup for all known infections associated with immune-mediated GBS was negative. The patient received treatment with intravenous immunoglobulin. Neurological examination 1 month after discharge showed full recovery and he regained his baseline functional status.

Conclusions

As far as we know, this is the first reported case in Tunisia. Although extremely rare, neurologists should remain vigilant for acute inflammatory demyelinating polyradiculoneuropathy after COVID-19 vaccination.

Understanding the approach of family physicians in Turkey to the problem of vaccine rejection

Vaccines not only protect individuals, but also prevent the spread of vaccine-preventable diseases in the community. Vaccine rejection in Turkey increased 125-fold between 2012 and 2019. Thus, this cross-sectional study aimed to investigate the level of knowledge of family physicians about vaccination, which can be the keystone of vaccine rejection. Evaluations were also made of vaccine recommendations, practice, and confidence in vaccine safety. The study was conducted using a 41-item questionnaire, completed by 804 (3.3%) family physicians serving in Turkey. The most common reasons for vaccine rejection were found to be fear of disease from the vaccine substance at the rate of 53.7% (n = 298), religious reasons at 32.3% (n = 179), disbelief of protection at 9.9% (n = 55), and fear of infertility at 4.1% (n = 23). Logistic regression analysis was applied to determine the factors affecting the power of the family physician's recommendation. The results showed that age >41 years (OR = 1.625 (1.129-2.34)), having self-efficacy (OR = 1.628 (1.183-2.24)) and belief in the usefulness of the vaccine made a positive contribution to the power to recommend vaccines (OR = 1.420 (1.996-1.012)). The results of this study demonstrated that training on vaccines and vaccine-preventable diseases has a positive effect on self-efficacy (p < .0001). This study can be considered of value as the first to demonstrate the beliefs and attitudes of family physicians in Turkey. Further training courses to increase knowledge of vaccines, vaccine-preventable diseases, and communication skills would be of benefit for family physicians.

Epidemiological Features and Economic Burden of Guillain-Barré Syndrome in South Korea: A Nationwide Population-Based Study

BACKGROUND AND PURPOSE

Guillain-Barré syndrome (GBS) is rare, but its symptoms are severe and they occasionally lead to long-term disability. Country-specific epidemiological evidence is useful for detecting potential problems at the population level. This study investigated the epidemiological and economic characteristics of GBS in South Korea.

METHODS

The Korean National Health Insurance Service claims data from 2010 to 2016 were used to identify incident cases as newly hospitalized patients with a primary diagnosis of GBS (the 10th revision of the International Classification Disease code of G61.0). New cases were defined as patients not having claim records for GBS within one year prior to the hospital admission for GBS.

RESULTS

The incidence rate increased by 45.6% between 2010 and 2016, from 1.28 to 1.82 per 100,000 population. All age groups other than <20 years showed increasing trends. The incidence rate was highest in those aged 65 years to 74 years. Approximately 72% of the incident GBS cases had antecedent infection within 42 days before GBS was diagnosed. Children younger than 10 years constituted the highest proportion of antecedent infections (93.7%). The average length of stay per GBS hospitalization was 33.5 days. Patients had an average of 7.48 outpatient visits for GBS treatment per year. The economic burden from a societal perspective of treating GBS during the first year was USD 16,428.

CONCLUSIONS

The increasing incidence trend and substantial economic burden of GBS strongly advocate the development of effective strategies for preventing and managing GBS.

Adverse events following HPV vaccination: 11 years of surveillance in Australia

BACKGROUND

Australia was the first country to implement a fully funded vaccination program with quadrivalent human papillomavirus vaccine (4vHPV) in 2007, including males from 2013. We examined adverse events (AE) following vaccination with 4vHPV from 11 years of post-marketing data, focusing on a period of enhanced surveillance and adverse events of special interest (AESI).

METHODS

AE following 4vHPV doses administered between April 2007 and December 2017 reported to Australia's national regulator, the Therapeutic Goods Administration, were examined; reports collected during enhanced surveillance in 2013 and 2014 were analyzed separately. Age and sex-specific rates, using denominator data from the national HPV vaccination register, were determined. Pre-specified AESI were identified using Medical Dictionary for Regulatory Activities (MedDRA®) Preferred Terms and examined in detail.

FINDINGS

Following nine million doses of 4vHPV vaccine administered in Australia, 4551 AE reports were identified. The crude reporting rate was 39.8 per 100 000 doses in the funded cohorts, excluding the enhanced surveillance period. The reported rate of syncope in 12 to 13-year-old males and females was 29.6 per 100 000 doses during enhanced surveillance and 7.1 per 100 000 doses during the remaining study period; rates of syncope were higher in younger compared to older adolescents. The rate of anaphylaxis (0.32 per 100 000 doses) was consistent with published rates. Other AESI including autoimmune disease, postural orthostatic tachycardia syndrome, primary ovarian insufficiency, Guillain-Barré syndrome, complex regional pain syndrome and venous thromboembolism, were reported at low rates and analysis did not reveal unexpected patterns that would suggest causal association.

INTERPRETATION

AESI, apart from syncope, were reported rarely. The higher rate of syncope among younger adolescents highlights the need for management protocols to prevent syncope-related injury. Analysis of this large, longitudinal dataset in a country with high vaccine uptake, including a period of enhanced surveillance, affirms the safety profile of 4vHPV.

Case of Paradoxical Cultural Sensitivity: Mixed Method Study of Web-Based Health Informational Materials About the Human Papillomavirus Vaccine in Israel

BACKGROUND

Designing web-based informational materials regarding the human papillomavirus (HPV) vaccine has become a challenge for designers and decision makers in the health authorities because of the scientific and public controversy regarding the vaccine's safety and effectiveness and the sexual and moral concerns related to its use.

OBJECTIVE

The study aimed to investigate how cultural sensitivity (CS) is articulated in the explanatory informational materials on the HPV vaccine that are posted on the websites of the Israeli health authorities. In addition, the study examined the effect of transparency on the expression of CS in the informational materials.

METHODS

The study employed a quantitative and qualitative content analysis of the texts of explanatory informational materials published on the Arabic and Hebrew websites of the Israel Ministry of Health and the Clalit health maintenance organization (HMO).

RESULTS

The findings revealed the differences in the dimensions of CS (based on the CS model by Resnicow) between the informational materials targeting the majority Jewish population and those targeting the minority Arab population. Indeed, the research findings point to a paradox. On the one hand, the materials appealing to the conservative Arab population exhibited CS, in that the sexual context of the vaccine was missing. On the other hand, analysis of Resnicow's deep dimensions showed that disregarding the sexual context does not allow the relevant target audience to reflect on the barriers and concerns. In addition, the way the information was provided exhibited a lack of transparency regarding the CS dimensions (surface and deep).

CONCLUSIONS

The public health authorities have 2 main objectives in the context of vaccinations. One is to raise the vaccination rates and the other is to provide full and culturally sensitive information to give the public the tools to make intelligent decisions. The findings of this study indicated that despite the high uptake rate for HPV vaccination in the Arab population, the health authorities did not exercise full transparency and CS in transmitting the association between engaging in sexual relations and the necessity of the vaccination. Thus, the major challenge for the health authorities is to find ways to implement the objective of communicating information about the vaccination in a way that is transparent and culturally sensitive, even if this raises questions and fears among the public deriving from their culture.

Safety concerns with human papilloma virus immunization in Japan: Analysis and evaluation of Nagoya City's surveillance data for adverse events

Aim

To assess the safety of human papilloma virus (HPV) vaccines by using data from the “Nagoya City Cervical Cancer Immunization Program Survey”.

Methods

Unadjusted odds ratios (OR) were calculated between HPV‐vaccinated cases and un‐vaccinated controls. Age‐stratified analyses were performed to evaluate the interaction between age and events. Adjusted ORs were also estimated with multiple logistic regression models.

Results

In the 15–16‐year‐old group, the unadjusted ORs were significantly higher for symptoms of memory impairment, dyscalculia, and involuntary movement. The age‐adjusted multivariate analyses demonstrated that the vaccinated cases were less likely than the unvaccinated controls to have experienced symptoms in almost all symptoms, except for two symptoms such as involuntary movement and weakness. However, study period‐adjusted multivariate analyses demonstrated that the vaccinated cases were significantly more likely than un‐vaccinated controls to have experienced symptoms of memory impairment and involuntary movement.

Conclusions

Based on our analysis using data from the Nagoya City surveillance survey, a possible association between HPV vaccination and distinct symptoms such as cognitive impairment or movement disorders exists. A consistent causal relationship between HPV vaccination and these symptoms remains uncertain. However, given the seriousness of symptoms, we believe that a more comprehensive and large‐scale study is essential to confirm the safety of HPV vaccination.

Safety of Human Papillomavirus Vaccines: An Updated Review

Human papillomavirus (HPV) vaccines are now included in immunisation programmes in 71 countries. Unfortunately, uptake has been impacted in some countries by reduced confidence in the safety of the HPV vaccine. In 2013, we published an extensive review demonstrating a reassuring safety profile for bivalent (2vHPV) and quadrivalent (4vHPV) vaccines. A nonavalent (9vHPV) vaccine is now available and HPV immunisation programmes have been extended to males in 11 countries. The aim of this updated narrative review was to examine the evidence on HPV vaccine safety, focusing on the 9vHPV vaccine, special populations and adverse events of special interest (AESI). The previous searches were replicated to identify studies to August 2016, including additional search terms for AESI. We identified 109 studies, including 15 population-based studies in over 2.5 million vaccinated individuals across six countries. All vaccines demonstrated an acceptable safety profile; injection-site reactions were slightly more common for 9vHPV vaccine than for 4vHPV vaccine. There was no consistent evidence of an increased risk of any AESI, including demyelinating syndromes or neurological conditions such as complex regional pain or postural orthostatic tachycardia syndromes. The risk-benefit profile for HPV vaccines remains highly favourable.

Human papillomavirus vaccine and demyelinating diseases-A systematic review and meta-analysis

Approved in 2006, human papillomavirus (HPV) vaccines were initially targeted for girls aged 9-14 years. Although the safety of these vaccines has been monitored through post-licensure surveillance programmes, cases of neurological events have been reported worldwide. The present study aimed to assess the risk of developing demyelination after HPV immunization by meta-analysing risk estimates from pharmacoepidemiologic studies. A systematic review was conducted in Medline, Embase, ISI Web of Science and the Cochrane Library from inception to 10 May 2017, without language restriction. Only observational studies including a control group were retained. Study selection was performed by two independent reviewers with disagreements solved through discussion. This meta-analysis was performed using a generic inverse variance random-effect model. Outcomes of interest included a broad category of central demyelination, multiple sclerosis (MS), optic neuritis (ON), and Guillain-Barré syndrome (GBS), each being considered independently. Heterogeneity was investigated; sensitivity and subgroup analyses were performed when necessary. In parallel, post-licensure safety studies were considered for a qualitative review. This study followed the PRISMA statement and the MOOSE reporting guideline. Of the 2,863 references identified, 11 articles were selected for meta-analysis. No significant association emerged between HPV vaccination and central demyelination, the pooled odds ratio being 0.96 [95% CI 0.77-1.20], with a moderate but non-significant heterogeneity (I² = 29%). Similar results were found for MS and ON. Sensitivity analyses did not alter our conclusions. Findings from qualitative review of 14 safety studies concluded in an absence of a relevant signal. Owing to limited data on GBS, no meta-analysis was performed for this outcome. This study strongly supports the absence of association between HPV vaccines and central demyelination.

Adverse events of vaccines and the consequences of non-vaccination: a critical review

OBJECTIVE

To analyze the risks related to vaccines and the impacts of non-vaccination on the world population.

METHODS

This is a narrative review that has considered information present in the bibliographic databases NCBI-PubMed, Medline, Lilacs, and Scientific Electronic Library Online (SciELO), between November 2015 and November 2016. For the analysis of outbreaks caused by non-vaccination, we considered the work published between 2010 and 2016.

RESULTS

We have described the main components of the vaccines offered by the Brazilian public health system and the adverse events associated with these elements. Except for local inflammatory reactions and rare events, such as exacerbation of autoimmune diseases and allergies, no causal relationship has been demonstrated between the administration of vaccines and autism, Alzheimer's disease, or narcolepsy. On the other hand, the lack of information and the dissemination of non-scientific information have contributed to the reemergence of infectious diseases in several countries in the world and they jeopardize global plans for the eradication of these diseases.

CONCLUSIONS

The population should be well informed about the benefits of vaccination and health professionals should assume the role of disseminating truthful information with scientific support on the subject, as an ethical and professional commitment to society.

Vaccines for preventing influenza in healthy adults

BACKGROUND

The consequences of influenza in adults are mainly time off work. Vaccination of pregnant women is recommended internationally. This is an update of a review published in 2014. Future updates of this review will be made only when new trials or vaccines become available. Observational data included in previous versions of the review have been retained for historical reasons but have not been updated due to their lack of influence on the review conclusions.

OBJECTIVES

To assess the effects (efficacy, effectiveness, and harm) of vaccines against influenza in healthy adults, including pregnant women.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 12), MEDLINE (January 1966 to 31 December 2016), Embase (1990 to 31 December 2016), the WHO International Clinical Trials Registry Platform (ICTRP; 1 July 2017), and ClinicalTrials.gov (1 July 2017), as well as checking the bibliographies of retrieved articles.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs comparing influenza vaccines with placebo or no intervention in naturally occurring influenza in healthy individuals aged 16 to 65 years. Previous versions of this review included observational comparative studies assessing serious and rare harms cohort and case-control studies. Due to the uncertain quality of observational (i.e. non-randomised) studies and their lack of influence on the review conclusions, we decided to update only randomised evidence. The searches for observational comparative studies are no longer updated.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We rated certainty of evidence for key outcomes (influenza, influenza-like illness (ILI), hospitalisation, and adverse effects) using GRADE.

MAIN RESULTS

We included 52 clinical trials of over 80,000 people assessing the safety and effectiveness of influenza vaccines. We have presented findings from 25 studies comparing inactivated parenteral influenza vaccine against placebo or do-nothing control groups as the most relevant to decision-making. The studies were conducted over single influenza seasons in North America, South America, and Europe between 1969 and 2009. We did not consider studies at high risk of bias to influence the results of our outcomes except for hospitalisation.Inactivated influenza vaccines probably reduce influenza in healthy adults from 2.3% without vaccination to 0.9% (risk ratio (RR) 0.41, 95% confidence interval (CI) 0.36 to 0.47; 71,221 participants; moderate-certainty evidence), and they probably reduce ILI from 21.5% to 18.1% (RR 0.84, 95% CI 0.75 to 0.95; 25,795 participants; moderate-certainty evidence; 71 healthy adults need to be vaccinated to prevent one of them experiencing influenza, and 29 healthy adults need to be vaccinated to prevent one of them experiencing an ILI). The difference between the two number needed to vaccinate (NNV) values depends on the different incidence of ILI and confirmed influenza among the study populations. Vaccination may lead to a small reduction in the risk of hospitalisation in healthy adults, from 14.7% to 14.1%, but the CI is wide and does not rule out a large benefit (RR 0.96, 95% CI 0.85 to 1.08; 11,924 participants; low-certainty evidence). Vaccines may lead to little or no small reduction in days off work (-0.04 days, 95% CI -0.14 days to 0.06; low-certainty evidence). Inactivated vaccines cause an increase in fever from 1.5% to 2.3%.We identified one RCT and one controlled clinical trial assessing the effects of vaccination in pregnant women. The efficacy of inactivated vaccine containing pH1N1 against influenza was 50% (95% CI 14% to 71%) in mothers (NNV 55), and 49% (95% CI 12% to 70%) in infants up to 24 weeks (NNV 56). No data were available on efficacy against seasonal influenza during pregnancy. Evidence from observational studies showed effectiveness of influenza vaccines against ILI in pregnant women to be 24% (95% CI 11% to 36%, NNV 94), and against influenza in newborns from vaccinated women to be 41% (95% CI 6% to 63%, NNV 27).Live aerosol vaccines have an overall effectiveness corresponding to an NNV of 46. The performance of one- or two-dose whole-virion 1968 to 1969 pandemic vaccines was higher (NNV 16) against ILI and (NNV 35) against influenza. There was limited impact on hospitalisations in the 1968 to 1969 pandemic (NNV 94). The administration of both seasonal and 2009 pandemic vaccines during pregnancy had no significant effect on abortion or neonatal death, but this was based on observational data sets.

AUTHORS' CONCLUSIONS

Healthy adults who receive inactivated parenteral influenza vaccine rather than no vaccine probably experience less influenza, from just over 2% to just under 1% (moderate-certainty evidence). They also probably experience less ILI following vaccination, but the degree of benefit when expressed in absolute terms varied across different settings. Variation in protection against ILI may be due in part to inconsistent symptom classification. Certainty of evidence for the small reductions in hospitalisations and time off work is low. Protection against influenza and ILI in mothers and newborns was smaller than the effects seen in other populations considered in this review.Vaccines increase the risk of a number of adverse events, including a small increase in fever, but rates of nausea and vomiting are uncertain. The protective effect of vaccination in pregnant women and newborns is also very modest. We did not find any evidence of an association between influenza vaccination and serious adverse events in the comparative studies considered in this review. Fifteen included RCTs were industry funded (29%).

Human papillomavirus vaccination and risk of autoimmune diseases: A large cohort study of over 2million young girls in France

BACKGROUND

Whether human papillomavirus (HPV) vaccination could induce or trigger autoimmune diseases (AID) has been questioned, and potentially contributes to low immunization coverage in France. This study evaluated the association between HPV vaccination and the risk of AID using routinely collected data sources.

METHODS

All girls aged 13-16years between 2008 and 2012, covered by the general health insurance scheme and without history of HPV vaccination or AID, were included and followed using French nationwide databases. Fourteen neurological, rheumatological, haematological, gastrointestinal or endocrine AID, were identified from ICD-10 codes allocated to hospital stays and long-term illnesses or by marker drugs. Their incidence was compared between girls exposed and non-exposed to HPV vaccination, using a Cox model adjusted for inclusion year, geographic area, socio-economic indicators, healthcare use level and other immunizations.

RESULTS

Among 2,252,716 girls, 37% received HPV vaccine and 4,096 AID occurred during a mean follow-up time of 33months. The incidence of AID was not increased after exposure to HPV vaccination, except for Guillain-Barré syndrome (GBS) (incidence rate of 1.4 among exposed [20 cases] versus 0.4 per 100,000 PY among unexposed [23 cases]; adjusted HR: 3.78 [1.79-7.98]). This association persisted across numerous sensitivity analyses and was particularly marked in the first months following vaccination. Under the hypothesis of a causal relationship, this would result in 1-2 GBS cases attributable to HPV vaccine per 100,000 girls vaccinated.

CONCLUSIONS

Our study provides reassuring results regarding the risk of AID after HPV vaccination, but an apparently increased risk of GBS was detected. Further studies are warranted to confirm this finding.

Evaluation of optic neuritis following human papillomavirus vaccination

To assess the relationship between human papillomavirus (HPV) vaccination and occurrence of optic neuritis (ON) and to evaluate a claims-based algorithm for identification of ON. Females of 9-26 year olds in the HealthCore's Integrated Research Database (HIRDSM) with and without claims evidence of HPV vaccination between 2007 and 2012 were included in this study. Potential ON cases were identified using the claims-based algorithm, positive predictive value (PPV) was determined using medical chart review. For the claims analysis, two study designs, a self-controlled temporal scan statistic and a retrospective matched cohort analysis, were used. ON was defined based on an algorithm developed using diagnosis and procedure codes from the medical claims. The PPV for ON cases using charts that had enough information for reviewers to make a determination was 62.5% (95% CI: 49.5%-74.3%). With the self-controlled temporal scan statistic, the primary analysis restricting on recommended vaccination schedule timing showed an increased risk of potential ON after second dose (RR = 3.39; p = 0.03), this finding was not confirmed for any of the additional analyses performed for individual or combined doses. With the cohort design, there was no increased risk of potential ON following vaccination in either individual or combined dose analyses. The risk of potential ON was higher among participants with a history of prior autoimmune diseases. In conclusion, identifying confirmed ON cases through administrative claims data proved challenging. The claims-based analysis in this study did not provide evidence for an association of ON with HPV vaccination.

No increased risk of Guillain-Barré syndrome after human papilloma virus vaccine: A self-controlled case-series study in England

OBJECTIVE

To investigate the risk of Guillain-Barré syndrome (GBS) after human papilloma virus (HPV) vaccine given to 12-18year old girls in England.

METHODS

Hospital Episode Statistics (HES) were searched using data to March 2016 to identify incident cases of GBS in female patients aged from 11 to 20years eligible to have received the HPV vaccine since its introduction as a 3 dose schedule in September 2008. Diagnosis was confirmed by the case's general practitioner (GP) who also provided HPV vaccination dates. The risk of admission within 3months (primary risk window) 6 and 12months of any dose was assessed using the self-controlled case-series (SCCS) method in vaccinated girls with age, season and time-period adjustment. The risk before and after the change in 2012 from bivalent vaccine to quadrivalent vaccine was also assessed.

RESULTS

A total 244 episodes were initially identified which reduced to 101 episodes in 100 girls when just including cases where the GP could be contacted, at least one vaccine dose was given, and GBS was confirmed or classed as probable. Nine, 14 and 24GBS admissions occurred within 3, 6, 12months of a dose respectively. The relative incidence (RI) for the 3month risk period was 1.04 (95% confidence interval 0.47-2.28), for the 6month period 0.83 (0.41-1.69) and for the 12month period 1.10 (0.57-2.14). When restricting to 79 confirmed cases the RI in the 3month risk period was 1.26 (0.55-2.92) and the RI 1.61 (0.39-6.54) for quadrivalent vaccine compared to 0.84 (0.30-2.34) for bivalent.

CONCLUSION

We found no evidence of an increased risk of GBS following HPV vaccination in England and, based on the upper end of the 95% CI for the RI and the number of HPV vaccine doses given in England, can exclude a risk of about 1 per million doses.

Autoimmune/Inflammatory Syndrome Induced by Adjuvants and Thyroid Autoimmunity

The autoimmune/inflammatory syndrome induced by adjuvants (ASIA), presented by Shoenfeld and Agmon-Levin in 2011, is an entity that incorporates diverse autoimmune conditions induced by the exposure to various adjuvants. Adjuvants are agents that entail the capability to induce immune reactions. Adjuvants are found in many vaccines and used mainly to increase the response to vaccination in the general population. Silicone has also been reported to be able to induce diverse immune reactions. Clinical cases and series of heterogeneous autoimmune conditions including systemic sclerosis, systemic lupus erythematosus, and rheumatoid arthritis have been reported to be induced by several adjuvants. However, only a small number of cases of autoimmune thyroid disorder have been included under the umbrella of ASIA syndrome. Indeed, clinical cases of Hashimoto's thyroiditis and/or subacute thyroiditis were observed after the exposure to vaccines as well as silicone implantation. In our review, we aimed to summarize the current knowledge on ASIA syndrome presented as endocrinopathies, focusing on autoimmune thyroid disorders associated with the various adjuvants.

Evolução do sistema público de saúde no Brasil frente ao estágio atual da prevenção do câncer de colo uterino em mulheres jovens e adolescentes

O câncer de colo uterino representa um problema de saúde pública em nível mundial, estando em grande parte dos casos relacionado com a infecção pelo papiloma vírus humano. O exame de Papanicolau é ainda o principal instrumento para o rastreamento das lesões precursoras. Contudo no Brasil, tal meio diagnóstico-preventivo é preconizado apenas para mulheres na faixa etária entre os 25 e 64 anos. Desse modo, este trabalho teve por objetivo prover uma revisão/atualização crítica da evolução e princípios do sistema de saúde público brasileiro diante da situação atual da prevenção do câncer de colo uterino em mulheres jovens e adolescentes. Ressalta-se que os problemas de saúde do Brasil passaram do período colonial, marcado pelas doenças pestilenciais, para a atualidade com a emergência de doenças crônicas a exemplo dos cânceres. Além disso, a literatura científica reporta taxas preocupantes para a ocorrência de alterações citopatológicas cérvico-vaginais em mulheres jovens e adolescentes no país defronte a diversos agravos neste contexto.  Assim sendo, a gestão da saúde no Brasil necessita de amplos ajustes  visando principalmente a inserção de mulheres e adolescentes de 10 a 24 anos nos programas de diagnóstico precoce do câncer de colo uterino.

Safety of human papillomavirus vaccines: a review

INTRODUCTION

Between 2006 and 2009, two different human papillomavirus virus (HPV) vaccines were licensed for use: a quadrivalent (qHPVv) and a bivalent (bHPVv) vaccine. Since 2008, HPV vaccination programmes have been implemented in the majority of the industrialized countries. Since 2013, HPV vaccination has been part of the national programs of 66 countries including almost all countries in North America and Western Europe. Despite all the efforts made by individual countries, coverage rates are lower than expected. Vaccine safety represents one of the main concerns associated with the lack of acceptance of HPV vaccination both in the European Union/European Economic Area and elsewhere.

AREAS COVERED

Safety data published on bivalent and quadrivalent HPV vaccines, both in pre-licensure and post-licensure phase, are reviewed.

EXPERT OPINION

Based on the latest scientific evidence, both HPV vaccines seem to be safe. Nevertheless, public concern and rumors about adverse events (AE) represent an important barrier to overcome in order to increase vaccine coverage. Passive surveillance of AEs is an important tool for detecting safety signals, but it should be complemented by activities aimed at assessing the real cause of all suspect AEs. Improved vaccine safety surveillance is the first step for effective communication based on scientific evidence.

Human papillomavirus vaccination: a case study in translational science

Each year 610,000 cases of anogenital and oropharyngeal cancers caused by human papillomavirus (HPV) occur worldwide. HPV vaccination represents a promising opportunity to prevent cancer on a global scale. The vaccine's story dates back to discoveries in chickens at the beginning of the 20th century with evidence that a cell-free filtrate could transmit the propensity to grow cancers. Later, studies with similarly derived filtrates from mammalian tumors showed that hosts could develop immunity to subsequent exposures. Epidemiologic studies linked cervical cancer to members of a family of viruses that cause papillomatosis and common warts. This led to work with DNA hybridization demonstrating a causal relationship. The formation of virus-like particles from viral capsid proteins led to the development of models for safe and effective vaccines. While much work remains with the acceptance of universal vaccination, the HPV vaccines Gardasil and Cervarix thus represent a century of successful translational research.

Vaccines for preventing influenza in healthy adults

BACKGROUND

Different types of influenza vaccines are currently produced worldwide. Vaccination of pregnant women is recommended internationally, while healthy adults are targeted in North America.

OBJECTIVES

To identify, retrieve and assess all studies evaluating the effects (efficacy, effectiveness and harm) of vaccines against influenza in healthy adults, including pregnant women.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 2), MEDLINE (January 1966 to May 2013) and EMBASE (1990 to May 2013).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs comparing influenza vaccines with placebo or no intervention in naturally occurring influenza in healthy individuals aged 16 to 65 years. We also included comparative studies assessing serious and rare harms.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

We included 90 reports containing 116 data sets; among these 69 were clinical trials of over 70,000 people, 27 were comparative cohort studies (about eight million people) and 20 were case-control studies (nearly 25,000 people). We retrieved 23 reports of the effectiveness and safety of vaccine administration in pregnant women (about 1.6 million mother-child couples).The overall effectiveness of parenteral inactivated vaccine against influenza-like illness (ILI) is limited, corresponding to a number needed to vaccinate (NNV) of 40 (95% confidence interval (CI) 26 to 128). The overall efficacy of inactivated vaccines in preventing confirmed influenza has a NNV of 71 (95% CI 64 to 80). The difference between these two values depends on the different incidence of ILI and confirmed influenza among the study populations: 15.6% of unvaccinated participants versus 9.9% of vaccinated participants developed ILI symptoms, whilst only 2.4% and 1.1%, respectively, developed laboratory-confirmed influenza.No RCTs assessing vaccination in pregnant women were found. The only evidence available comes from observational studies with modest methodological quality. On this basis, vaccination shows very limited effects: NNV 92 (95% CI 63 to 201) against ILI in pregnant women and NNV 27 (95% CI 18 to 185) against laboratory-confirmed influenza in newborns from vaccinated women.Live aerosol vaccines have an overall effectiveness corresponding to a NNV 46 (95% CI 29 to 115).The performance of one-dose or two-dose whole virion pandemic vaccines was higher, showing a NNV of 16 (95% CI 14 to 20) against ILI and a NNV of 35 (95% CI 33 to 47) against influenza, while a limited impact on hospitalisation was found (NNV 94, 95% CI 70 to 1022).Vaccination had a modest effect on time off work and had no effect on hospital admissions or complication rates. Inactivated vaccines caused local harms. No evidence of association with serious adverse events was found, but the harms evidence base was limited.The overall risk of bias in the included trials is unclear because it was not possible to assess the real impact of bias.

AUTHORS' CONCLUSIONS

Influenza vaccines have a very modest effect in reducing influenza symptoms and working days lost in the general population, including pregnant women. No evidence of association between influenza vaccination and serious adverse events was found in the comparative studies considered in the review. This review includes 90 studies, 24 of which (26.7%) were funded totally or partially by industry. Out of the 48 RCTs, 17 were industry-funded (35.4%).

Guillain-Barre syndrome following quadrivalent human papillomavirus vaccination among vaccine-eligible individuals in the United States

Post-marketing surveillance studies provide conflicting evidence about whether Guillain-Barre syndrome occurs more frequently following quadrivalent human papillomavirus (HPV4) vaccination. We aimed to assess whether Guillain-Barre syndrome is reported more frequently following HPV4 vaccination than other vaccinations among females and males aged 9 to 26 y in the United States. We used adverse event reports received by the United States Vaccine Adverse Event Reporting System (VAERS) between January 1, 2010 and December 31, 2012 to estimate overall, age-, and sex-specific proportional reporting ratios (PRRs) and corresponding Χ2 values for reports of Guillain-Barre syndrome between 5 and 42 d following HPV vaccination. Minimum criteria for a signal using this approach are 3 or more cases, PRR≥2, and Χ2≥4. Guillain-Barre syndrome was listed as an adverse event in 45 of 14,822 reports, of which 9 reports followed HPV4 vaccination and 36 reports followed all other vaccines. The overall, age-, and sex-specific PRR estimates were uniformly below 1. In addition, the overall, age-, and sex-specific Χ2 values were uniformly below 3. Our analysis of post-marketing surveillance data does not suggest that Guillain-Barre syndrome is reported more frequently following HPV4 vaccination than other vaccinations among vaccine-eligible females or males in the United States. Our findings may be useful when discussing the risks and benefits of HPV4 vaccination.

[The first vaccine against cancer: the human papillomavirus vaccine]

The last 20 years is one of the most remarkable periods in the fight against cancer, with the realization that some human papillomaviruses are causally related to cancer and with the development of the vaccine against human papillomavirus infections. This is a historical event in medicine and the prophylactic human papillomavirus vaccines have provided powerful tools for primary prevention of cervical cancer and other human papillomavirus-associated diseases. This is very important as human papillomavirus infection is probably the most common sexually transmitted infection worldwide, and over one million women develop associated cancer yearly, which is about 5% of all female cancers, and half of them die of their disease. Cancers associated with oncogenic human papillomaviruses, mostly HPV16 and 18, include cervical cancer (100%), anal cancer (95%), vulvar cancer (40%), vaginal cancer (60%), penile cancer (40%), and oro-pharingeal cancers (65%). In addition, pre-cancers such as genital warts and the rare recurrent respiratory papillomatosis are also preventable by vaccination. Currently, the human papillomavirus vaccines have the potential to significantly reduce the burden of human papillomavirus associated conditions, including prevention of up to 70% of cervical cancers. Two prophylactic human papillomavirus vaccines are currently available worldwide: a bivalent vaccine (types 16 and 18), and a quadrivalent vaccine (types 6, 11, 16, and 18). Randomized controlled trials conducted on several continents during the last 10 years have demonstrated that these vaccines are safe without serious side effects; they are highly immunogenic and efficacious in preventing incident and persistent vaccine-type human papillomavirus infections, high grade cervical, vulvar and vaginal intraepithelial neoplasia and so on. In addition, the quadrivalent vaccine has been shown to prevent genital warts in women and men. The vaccine is most effective when given to human papillomavirus naive girls. The human papillomavirus vaccines have been incorporated into national immunization programs in 22 European countries. Routine vaccination is recommended for girls aged between 9 and 13 years and catch-up vaccination for females between 13 and 25 years of age. There is no excuse not to incorporate the vaccines into the Hungarian national immunization program. Albeit vaccination is expensive, it is cost-effective in the long run definitely. Anyway, vaccination is a matter of the specialty and the national health program, but not of business. We all are obliged to prevent human suffering.

Human papillomavirus vaccine and systemic lupus erythematosus

To investigate the association between human papillomavirus (HPV) vaccination and autoimmune manifestations compatible with systemic lupus erythematosus (SLE) or SLE-like disease, the medical history of six women who presented with SLE or SLE-like disease following HPV immunization was collected. Data regarding type of vaccine, number of immunization, family and personal, clinical and serological features, as well as response to treatments were analyzed. In the reported cases, several common features were observed, such as personal or familial susceptibility to autoimmunity or adverse response to a prior dose of the vaccine, both of which may be associated with a higher risk of post-vaccination autoimmunity. Favorable response to immunosuppressant was observed in all patients. In the current study, a temporal association between immunization with HPV vaccine and the appearance of a spectrum of SLE-like conditions is reported. Additionally, among the patients described, several common features were observed that may enable better identification of subjects at risk. Further studies are required to assess the safety of immunization with the HPV vaccine in patients with autoimmune-rheumatic diseases or in subject at risk of autoimmunity as well as the potential beneficial effect of preventive immunosuppressants.

The two-faced T cell epitope: examining the host-microbe interface with JanusMatrix

Advances in the field of T cell immunology have contributed to the understanding that cross-reactivity is an intrinsic characteristic of the T cell receptor (TCR), and that each TCR can potentially interact with many different T cell epitopes. To better define the potential for TCR cross-reactivity between epitopes derived from the human genome, the human microbiome, and human pathogens, we developed a new immunoinformatics tool, JanusMatrix, that represents an extension of the validated T cell epitope mapping tool, EpiMatrix. Initial explorations, summarized in this synopsis, have uncovered what appear to be important differences in the TCR cross-reactivity of selected regulatory and effector T cell epitopes with other epitopes in the human genome, human microbiome, and selected human pathogens. In addition to exploring the T cell epitope relationships between human self, commensal and pathogen, JanusMatrix may also be useful to explore some aspects of heterologous immunity and to examine T cell epitope relatedness between pathogens to which humans are exposed (Dengue serotypes, or HCV and Influenza, for example). In Hand-Foot-Mouth disease (HFMD) for example, extensive enterovirus and human microbiome cross-reactivity (and limited cross-reactivity with the human genome) seemingly predicts immunodominance. In contrast, more extensive cross-reactivity with proteins contained in the human genome as compared to the human microbiome was observed for selected Treg epitopes. While it may be impossible to predict all immune response influences, the availability of sequence data from the human genome, the human microbiome, and an array of human pathogens and vaccines has made computationally–driven exploration of the effects of T cell epitope cross-reactivity now possible. This is the first description of JanusMatrix, an algorithm that assesses TCR cross-reactivity that may contribute to a means of predicting the phenotype of T cells responding to selected T cell epitopes. Whether used for explorations of T cell phenotype or for evaluating cross-conservation between related viral strains at the TCR face of viral epitopes, further JanusMatrix studies may contribute to developing safer, more effective vaccines.

HPV vaccines and cancer prevention, science versus activism

The rationale behind current worldwide human papilloma virus (HPV) vaccination programs starts from two basic premises, 1) that HPV vaccines will prevent cervical cancers and save lives and, 2) have no risk of serious side effects. Therefore, efforts should be made to get as many pre-adolescent girls vaccinated in order to decrease the burden of cervical cancer. Careful analysis of HPV vaccine pre- and post-licensure data shows however that both of these premises are at odds with factual evidence and are largely derived from significant misinterpretation of available data.

The Guillain-Barré syndrome

The latest estimation for the frequency of Guillain-Barré syndrome (GBS) is 1.1 to 1.8 per 100000 persons per year. Guillain-Barré syndrome is today divided into two major subtypes: acute inflammatory demyelinating polyneuropathy (AIDP) and the axonal subtypes, acute motor axonal neuropathy (AMAN) and acute motor and sensory axonal neuropathy (AMSAN). The axonal forms of GBS are caused by certain autoimmune mechanisms, due to a molecular mimicry between antecedent bacterial infection (particularly Campylobacter jejuni) and human peripheral nerve gangliosides. Improvements in patient management in intensive care units has permitted a dramatic drop in mortality rates. Immunotherapy, including plasma exchange (PE) or intravenous immunoglobulin (IVIg), seems to shorten the time to recovery, but their effect remains limited. Further clinical investigations are needed to assess the effect of PE or IVIg on the GBS patients with mild affection, no response, or relapse.

A review of clinical trials of human papillomavirus prophylactic vaccines

End of study analyses of the phase III trials of prophylactic human papillomavirus (HPV) virus-like particle (VLP) vaccines in young women are now largely completed. Two distinct vaccines were evaluated, Gardasil(®) (Merck & Co., Whitehouse Station, NJ USA) a quadrivalent vaccine containing VLPs of types 6, 11, 16 and 18 and Cervarix(®) (GlaxoSmithKline Biologicals, Rixensart, Belgium), a bivalent vaccine containing VLPs of types 16 and 18. Both vaccines exhibited excellent safety and immunogenicity profiles. The vaccines also demonstrated remarkably high and similar efficacy against the vaccine-targeted types for a range of cervical endpoints from persistent infection to cervical intraepithelial neoplasia grade 3 (CIN3) in women naïve to the corresponding type at the time of vaccination. However, protection from incident infection or disease from non-vaccine types was restricted, and the vaccines had no effect on prevalent infection or disease. Gardasil(®) also demonstrated strong protection against genital warts and vulvar/vaginal neoplasia associated with the vaccine types. In other trials, Gardasil(®) protected mid-adult women from incident infection and CIN caused by the vaccine types and protected men for incident infection, genital warts and anal intraepithelial neoplasia by the vaccine types. Cervarix(®) protected against vaccine-targeted anal infections in women in an end of study evaluation. For practical reasons, efficacy studies have not been conducted in the primary target populations of current vaccination programs, adolescent girls and boys. However, immunogenicity bridging studies demonstrating excellent safety and strong immune responses in adolescence, coupled with the documentation of durable antibody responses and protection in young adults, leads to an optimistic projection of the effectiveness of the vaccines in adolescent vaccination programs. Taken together, the excellent clinical trial results strongly support the potential of the vaccines as high value public health interventions and justify their widespread implementation to prevent anogenital HPV infections and their associated neoplasia. This article forms part of a special supplement entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.

Guillain-Barré syndrome after H1N1 vaccination in the United States: a report using the CDC/FDA Vaccine Adverse Event Reporting System (2009)

BACKGROUND

Although the Guillain-Barré syndrome (GBS) can be associated with the seasonal influenza vaccine, there is no definite evidence that GBS is associated with H1N1 influenza vaccination. The objective of this report is to study the occurrence and characteristics of GBS after H1N1 vaccine administration in the United States in 2009.

METHODS

Data were acquired from the Vaccine Adverse Event Reporting System and supplemented by additional information obtained from the Center for Biologics Evaluation and Research, under the Federal Freedom of Information Act.

RESULTS

A total of 62 individuals (mean age 46.51 ± 22.41 years), 33 of whom were men, developed GBS associated with the H1N1 influenza vaccination in 2009. Sixty GBS cases were reported within 6 weeks after vaccination, with 31 cases (50.0%) reported in the first 2 weeks. The estimated rate of occurrence of GBS was 6.2 cases per 10 million vaccinations, which is comparable to the rate of GBS in the general population.

CONCLUSION

The higher rate of GBS reports in the first 6 weeks after H1N1 vaccination suggests that some GBS cases may be triggered by H1N1 vaccination. This warrants early recognition, treatment, and active surveillance in the postvaccination setting.

Cost-effectiveness of routine vaccination of adolescent females against cytomegalovirus

BACKGROUND

Congenital cytomegalovirus (CMV) infection is associated with significant infant morbidity and mortality. A prophylactic vaccine to prevent congenital CMV infection is expected to be available in the near future, and will likely be targeted to adolescent females.

METHODS

Using a decision tree, we compared the costs, potential clinical impacts, and cost-effectiveness of the current strategy of no CMV vaccination versus a strategy where all adolescent females are vaccinated against CMV prior to their first pregnancy. Both maternal outcomes related to vaccination, and infant outcomes related to congenital CMV infection, were considered in the model.

RESULTS

Under base-case conditions, our analysis suggested that vaccinating all adolescent females against cytomegalovirus would be both less costly and with greater clinical benefits than not vaccinating. Among a population of 100,000 adolescent females, the vaccination strategy cost $32.3 million dollars less than not vaccinating, and avoided substantial numbers of infants affected with hearing loss, vision loss, and mental retardation, and 8 infant deaths. Our model was most sensitive to variations in vaccine efficacy. When vaccine efficacy against disease was less than 61%, not vaccinating became the preferred strategy because it was less expensive than vaccinating, without substantial changes in clinical benefits to the population.

CONCLUSIONS

Under a wide variety of conditions, universal vaccination of adolescent females to protect their future children against congenital CMV infection was cost effective. However, for this to be preferred over not vaccinating, our results suggest that vaccine efficacy against disease would need to be at least 61%.