Association between Guillain-Barré syndrome and influenza A (H1N1) 2009 monovalent inactivated vaccines in the USA: a meta-analysis

Guillain-Barré syndrome

Guillain-Barré syndrome is the most common cause of acute flaccid paralysis worldwide. Most patients present with an antecedent illness, most commonly upper respiratory tract infection, before the onset of progressive motor weakness. Several microorganisms have been associated with Guillain-Barré syndrome, most notably Campylobacter jejuni, Zika virus, and in 2020, the severe acute respiratory syndrome coronavirus 2. In C jejuni-related Guillain-Barré syndrome, there is good evidence to support an autoantibody-mediated immune process that is triggered by molecular mimicry between structural components of peripheral nerves and the microorganism. Making a diagnosis of so-called classical Guillain-Barré syndrome is straightforward; however, the existing diagnostic criteria have limitations and can result in some variants of the syndrome being missed. Most patients with Guillain-Barré syndrome do well with immunotherapy, but a substantial proportion are left with disability, and death can occur. Results from the International Guillain-Barré Syndrome Outcome Study suggest that geographical variations exist in Guillain-Barré syndrome, including insufficient access to immunotherapy in low-income countries. There is a need to provide improved access to treatment for all patients with Guillain-Barré syndrome, and to develop effective disease-modifying therapies that can limit the extent of nerve injury. Clinical trials are currently underway to investigate some of the potential therapeutic candidates, including complement inhibitors, which, together with emerging data from large international collaborative studies on the syndrome, will contribute substantially to understanding the many facets of this disease.

Influenza vaccination in autoimmune neuromuscular diseases: A survey of current practices and perceptions

INTRODUCTION

Recommendations for receiving the influenza vaccination in patients with autoimmune neuromuscular disorders, such as myasthenia gravis (MG), chronic inflammatory demyelinating polyneuropathy (CIDP), or Guillain-Barré syndrome (GBS), may vary among neurology practitioners. This survey examined the current practices and perceptions of neurologists regarding the influenza vaccination in these patients.

METHODS

We performed an Internet-based survey among neurologists across the United States through online forums for neurologists.

RESULTS

Across practice settings, 184 neurologists followed 6465 MG, 2313 CIDP, and 1907 GBS patients. Among the respondents, 82.6%, 58.8%, and 42.3% reported that they recommend the influenza vaccine for all patients with MG, CIDP, and GBS, respectively. Respondents practicing for more than 10 y were more conservative in recommending the influenza vaccine for all patients with MG. A history of exacerbation following the influenza vaccine was regarded as the most important factor influencing vaccine recommendation for MG and CIDP.

DISCUSSION

Influenza vaccination recommendation practices varied between surveyed neurologists, despite existing guidelines. Clearer professional society recommendations and education are an unmet need based on this apparent knowledge gap.

Ethical and policy implications of vaccinomics in the United States: community members' perspectives

Objectives: We aimed to elucidate public values regarding the use of genomics to improve vaccine development and use (vaccinomics).

Methods: Adults ≥18 years-old were recruited through social media and community organizations, and randomly assigned to one of four nested discussion groups in Boulder, CO and Baltimore, MD. Participants rated their confidence in vaccine safety and effectiveness prior to and after discussing vaccinomics. Before departing, they prioritized funding for vaccinomics versus federal priorities (vaccine safety and efficacy, new vaccines, and free vaccines) and chronic diseases (cancer, heart disease, and diabetes). Grounded Theory-influenced methods were used to identify themes.

Results: Participants broadly supported vaccinomics. Emergent themes: concerns about reduced privacy/confidentiality, increased genetically based stigma/discrimination, and reduced agency to make vaccine-related decisions through genetically based prioritization. Participants supported vaccinomics’ potential for increased personalization. Some participants favored prioritizing others over themselves during a vaccine shortage, while others did not. Some participants worried health insurance companies would discriminate against them based on information discovered through vaccinomics. Participants feared inequitable implementation of vaccinomics would contribute to discrimination and marginalization of vulnerable populations. Discussing vaccinomics did not impact perceptions of vaccine safety and effectiveness. Federal funding for vaccinomics was broadly supported.

Conclusion: Participants supported vaccinomics’ potential for increased personalization, noting policy safeguards to facilitate equitable implementation and protect privacy were needed. Despite some concerns, participants hoped vaccinomics would improve vaccine safety and effectiveness. Policies regarding vaccinomics’ implementation must address public concerns about the privacy and confidentiality of genetic information and potential inequities in access to vaccinomics’ benefits.

Prediction of post-vaccination Guillain-Barré syndrome using data from a passive surveillance system

Purpose

Severe adverse events (AEs), such as Guillain‐Barré syndrome (GBS) occur rarely after influenza vaccination. We identify highly associated AEs with GBS and develop prediction models for GBS using the US Vaccine Adverse Event Reporting System (VAERS) reports following trivalent influenza vaccination (FLU3).

Methods

This study analyzed 80 059 reports from the US VAERS between 1990 and 2017. Several AEs were identified as highly associated with GBS and were used to develop the prediction model. Some common and mild AEs that were suspected to be underreported when GBS occurred simultaneously were removed from the final model. The analyses were validated using European influenza vaccine AEs data from EudraVigilance.

Results

Of the 80 059 reports, 1185 (1.5%) were annotated as GBS related. Twenty‐four AEs were identified as having strong association with GBS. The full prediction model, using age, sex, and all 24 AEs achieved an area under the receiver operating characteristic (ROC) curve (AUC) of 85.4% (90% CI: [83.8%, 86.9%]). After excluding the nine (e.g., pruritus, rash, injection site pain) likely underreported AEs, the final AUC became 77.5% (90% CI: [75.5%, 79.6%]). Two hundred and one (0.25%) reports were predicted as of high risk of GBS (predicted probability >25%) and 84 actually developed GBS.

Conclusion

The prediction performance demonstrated the potential of developing risk‐prediction models utilizing the VAERS cohort. Excluding the likely underreported AEs sacrificed some prediction power but made the model more interpretable and feasible. The high absolute risk of even a small number of AE combinations suggests the promise of GBS prediction within the VAERS dataset.

Bayesian Network to Predict the Risk of Post Influenza Vaccination Guillain-Barré Syndrome: A Development and Validation Study (Preprint)

Background

Identifying the key factors of Guillain-Barré syndrome (GBS) and predicting its occurrence are vital for improving the prognosis of patients with GBS. However, there are scarcely any publications on a forewarning model of GBS. A Bayesian network (BN) model, which is known to be an accurate, interpretable, and interaction-sensitive graph model in many similar domains, is worth trying in GBS risk prediction.

Objective

The aim of this study is to determine the most significant factors of GBS and further develop and validate a BN model for predicting GBS risk.

Methods

Large-scale influenza vaccine postmarketing surveillance data, including 79,165 US (obtained from the Vaccine Adverse Event Reporting System between 1990 and 2017) and 12,495 European (obtained from the EudraVigilance system between 2003 and 2016) adverse events (AEs) reports, were extracted for model development and validation. GBS, age, gender, and the top 50 prevalent AEs were included for initial BN construction using the R package bnlearn.

Results

Age, gender, and 10 AEs were identified as the most significant factors of GBS. The posttest probability of GBS suggested that male vaccinees aged 50-64 years and without erythema should be on the alert or be warned by clinicians about an increased risk of GBS, especially when they also experience symptoms of asthenia, hypesthesia, muscular weakness, or paresthesia. The established BN model achieved an area under the receiver operating characteristic curve of 0.866 (95% CI 0.865-0.867), sensitivity of 0.752 (95% CI 0.749-0.756), specificity of 0.882 (95% CI 0.879-0.885), and accuracy of 0.882 (95% CI 0.879-0.884) for predicting GBS risk during the internal validation and obtained values of 0.829, 0.673, 0.854, and 0.843 for area under the receiver operating characteristic curve, sensitivity, specificity, and accuracy, respectively, during the external validation.

Conclusions

The findings of this study illustrated that a BN model can effectively identify the most significant factors of GBS, improve understanding of the complex interactions among different postvaccination symptoms through its graphical representation, and accurately predict the risk of GBS. The established BN model could further assist clinical decision-making by providing an estimated risk of GBS for a specific vaccinee or be developed into an open-access platform for vaccinees’ self-monitoring.

Guillain-Barré Syndrome After High-Dose Influenza Vaccine Administration in the United States, 2018-2019 Season

BACKGROUND

The Vaccine Safety Datalink (VSD) identified a statistical signal for an increased risk of Guillain-Barré syndrome (GBS) in days 1-42 after 2018-2019 high-dose influenza vaccine (IIV3-HD) administration. We evaluated the signal using Medicare.

METHODS

We conducted early- and end-of-season claims-based self-controlled risk interval analyses among Medicare beneficiaries ages ≥65 years, using days 8-21 and 1-42 postvaccination as risk windows and days 43-84 as control window. The VSD conducted chart-confirmed analyses.

RESULTS

Among 7 453 690 IIV3-HD vaccinations, we did not detect a statistically significant increased GBS risk for either the 8- to 21-day (odds ratio [OR], 1.85; 95% confidence interval [CI], 0.99-3.44) or 1- to 42-day (OR, 1.31; 95% CI, 0.78-2.18) risk windows. The findings from the end-of-season analyses were fully consistent with the early-season analyses for both the 8- to 21-day (OR, 1.64; 95% CI, 0.92-2.91) and 1- to 42-day (OR, 1.12; 95% CI, 0.70-1.79) risk windows. The VSD's chart-confirmed analysis, involving 646 996 IIV3-HD vaccinations, with 1 case each in the risk and control windows, yielded a relative risk of 1.00 (95% CI, 0.06-15.99).

CONCLUSIONS

The Medicare analyses did not exclude an association between IIV3-HD and GBS, but it determined that, if such a risk existed, it was similar in magnitude to prior seasons. Chart-confirmed VSD results did not confirm an increased risk of GBS.

Vaccine-Associated Neurological Adverse Events: A Case Report and Literature Review

Vaccination is an effective strategy to reduce the burden of preventable illness. However, many clinical reports revealed that various vaccinations may associate with neurological disorders, mainly including autoimmune disease, febrile seizure, and vaccine-associated paralytic poliomyelitis (VAPP). Although more and more reports revealed that part of the above post-vaccine neurological disorders is not directly related to vaccination, it may be merely a coincidence. However, these reports may increase the hesitancy on vaccination for the public population and influence the coverage of vaccination. In this report, we described a child with acute flaccid paralysis possibly caused by a poliovirus vaccine. To provide feasible ways to realize or reduce the risk of neurological adverse events caused by vaccines, we further provide a mini-review of the literature of vaccination associated with neurological adverse events. This revealed that oral poliomyelitis vaccine use exclusively and type 2 serotype poliomyelitis vaccine virus were the risk factors for VAPP. The combination vaccine was associated with an increased risk of ADEM and FS following immunization when compared with the administration of vaccines separately. Even though cases have been reported that vaccination may be a trigger of anti-NMDARe and GBS, there is no direct evidence to prove that vaccination increased the risk of GBS and anti-NMDARe.

Antigenic Variability a Potential Factor in Assessing Relationship Between Guillain Barré Syndrome and Influenza Vaccine - Up to Date Literature Review

Guillain-Barré syndrome (GBS) is a possible serious adverse event of the influenza vaccine but it is yet to be proven. The objective of our traditional literature review is to assess the potential relationship between GBS and influenza vaccine. A traditional literature review has been carried out by selecting 26 articles from PubMed published between 2011 and 2020. Twenty-six articles met the selection criteria (eight observational studies, four systematic literature review, three meta-analyses, two case-control, two retrospective cohort, and seven case series). Selected studies were focused on monitoring the safety of influenza vaccines, the relative safety of pandemic and seasonal influenza vaccines, influenza vaccine a potential etiology of GBS, and pathogenesis of post-vaccination GBS. Few studies have shown a higher incidence of GBS with a pandemic influenza vaccine compared to the seasonal influenza vaccine, while several studies have concluded a small increase in the possibility of GBS following any type of influenza vaccine. There were some studies that estimated no association possibly due to the presence of confounding factors such as influenza-like illness, low power of the study, and reporting bias in post-vaccination surveillance programs. GSB should be taken into consideration as one of the less common but serious side effects of the influenza vaccine but it should not adversely affect the acceptance of the influenza vaccination program. Continuous monitoring of influenza vaccine safety should be performed regularly.

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.

[Recommendations on the approach when unusual neurological symptoms occur in temporal association with vaccinations in childhood and adolescence]

Vaccinations are often administered at an age when many neurological diseases of childhood and adolescence also occur. Febrile seizures may occur following vaccination in patients with an appropriate genetic predisposition. The occurrence of narcolepsy has been described more frequently after pandemic influenza A-H1N1 vaccinations. The causality has not been proven. Data regarding an association between Guillain-Barré syndrome and influenza vaccinations are inconclusive. It was conclusively shown that vaccinations do not cause neurological disorders, such as autism and do not trigger multiple sclerosis. In summary, there is currently no confirmed evidence for the occurrence of chronic neurological diseases as a consequence of generally recommended vaccinations in Germany. If unusual neurological symptoms are observed in temporal association with vaccinations, a comprehensive evaluation is necessary to exclude a causal relationship and to diagnose the underlying neurological disease independent of the vaccination. This statement gives specific recommendations for the practical approach when neurological symptoms are observed in temporal association with vaccinations with respect to taking the patient history, initial diagnostic procedures, accurate and prompt documentation and the obligation to report the event. The committee also proposes procedures for further clarification and differential diagnostics of causal neurological diseases in childhood and adolescence.

COVID-19 and neuromuscular disorders

The coronavirus 2019 (COVID-19) pandemic has potential to disproportionately and severely affect patients with neuromuscular disorders. In a short period of time, it has already caused reorganization of neuromuscular clinical care delivery and education, which will likely have lasting effects on the field. This article reviews (1) potential neuromuscular complications of COVID-19, (2) assessment and mitigation of COVID-19-related risk for patients with preexisting neuromuscular disease, (3) guidance for management of immunosuppressive and immunomodulatory therapies, (4) practical guidance regarding neuromuscular care delivery, telemedicine, and education, and (5) effect on neuromuscular research. We outline key unanswered clinical questions and highlight the need for team-based and interspecialty collaboration. Primary goals of clinical research during this time are to develop evidence-based best practices and to minimize morbidity and mortality related to COVID-19 for patients with neuromuscular disorders.

The state of vaccine safety science: systematic reviews of the evidence

This Review updates the scientific evidence assessing possible causal associations of adverse events following immunisation (AEFI) compiled in the 2012 report from the Institute of Medicine and the 2014 report from the Agency for Healthcare Research and Quality. For 12 of 46 AEFI examined, a causal relationship has been established with at least one vaccine currently routinely recommended to the general USA population: anaphylaxis, arthralgia or arthritis (mild, acute, and transient, not chronic), deltoid bursitis (when vaccine is administered improperly), disseminated varicella infection (in immune deficient individuals for whom the varicella vaccine is contraindicated), encephalitis, febrile seizures, Guillain-Barré syndrome, hepatitis (in immune deficient individuals for whom the varicella vaccine is contraindicated), herpes zoster, immune thrombocytopenic purpura, meningitis, and syncope. Other than mild acute and transient arthralgia or arthritis, which is very common in adult women after rubella vaccine, these adverse reactions are rare or very rare. Vaccines have an excellent safety profile overall and provide protection against infectious diseases to individuals and the general population.

Is an Increased Risk of Developing Guillain-Barré Syndrome Associated with Seasonal Influenza Vaccination? A Systematic Review and Meta-Analysis

While the weight of epidemiological evidence does not support a causal link with influenza vaccination evaluated over the last 30 years, Guillain–Barré syndrome (GBS) has been considered a vaccine-associated adverse event of interest since 1976. To investigate the existence of GBS risk after vaccination against seasonal influenza, a systematic review and meta-analysis have been conducted based on 22 eligible epidemiological studies from 1981 to 2019 reporting 26 effect sizes (ESs) in different influenza seasons. The primary result of our meta-analysis pointed to no risk of vaccine-associated GBS, as documented by a pooled ES of 1.15 (95% CI: 0.97–1.35). Conversely, an obvious high risk of GBS was observed in patients with previous influenza-like illness (ILI), as demonstrated by a pooled ES of 9.6 (95% CI: 4.0–23.0) resulting from a supplementary analysis. While the meta-analysis did not confirm the putative risk of vaccine-associated GBS suggested by many epidemiological studies, vaccination against seasonal influenza reduced the risk of developing ILI-associated GBS by about 88%. However, to obtain strong evidence, more epidemiological studies are warranted to establish a possible coincidence between vaccination and ILI prior to GBS onset.

Axonal variants of Guillain-Barré syndrome: an update

Axonal variants of Guillain-Barré syndrome (GBS) mainly include acute motor axonal neuropathy, acute motor and sensory axonal neuropathy, and pharyngeal-cervical-brachial weakness. Molecular mimicry of human gangliosides by a pathogen's lipooligosaccharides is a well-established mechanism for Campylobacter jejuni-associated GBS. New triggers of the axonal variants of GBS (axonal GBS), such as Zika virus, hepatitis viruses, intravenous administration of ganglioside, vaccination, and surgery, are being identified. However, the pathogenetic mechanisms of axonal GBS related to antecedent bacterial or viral infections other than Campylobacter jejuni remain unknown. Currently, autoantibody classification and serial electrophysiology are cardinal approaches to differentiate axonal GBS from the prototype of GBS, acute inflammatory demyelinating polyneuropathy. Newly developed technologies, including metabolite analysis, peripheral nerve ultrasound, and feature selection via artificial intelligence are facilitating more accurate diagnosis of axonal GBS. Nevertheless, some key issues, such as genetic susceptibilities, remain unanswered and moreover, current therapies bear limitations. Although several therapies have shown considerable benefits to experimental animals, randomized controlled trials are still needed to validate their efficacy.

Seasonal influenza vaccine and Guillain-Barré syndrome: A self-controlled case series study

OBJECTIVE

To evaluate the risk of Guillain-Barré syndrome (GBS) following seasonal influenza vaccination based on French nationwide data.

METHODS

All cases of GBS occurring in metropolitan France between September 1 and March 31 from 2010 to 2014 were identified from the French national health data system. Data were analyzed according to the self-controlled case series method. The risk period started 1 day after the patient received vaccine (D1) until 42 days after vaccination (D42). The incidence of GBS during this risk period was compared to that of the control period (D43-March 31). The incidence rate ratio (IRR) was estimated after adjusting for seasonality and presence or not of acute infections.

RESULTS

Between September and March, of the 2010/2011 to 2013/2014 influenza vaccination seasons, 3,523 cases of GBS occurred in metropolitan France and were included in the study. Among them, 15% (527 patients) had received influenza vaccination. A total of 140 patients developed GBS during the 42 days following influenza vaccination. The crude risk of developing GBS was not significantly increased during the 42 days following influenza vaccination (IRR, 1.02; 95% confidence interval [CI], 0.83-1.25; p = 0.85). This result remained nonsignificant after adjustment for calendar months and the incidence of acute gastrointestinal and respiratory tract infections (IRR, 1.10; 95% CI, 0.89-1.37; p = 0.38). In contrast, the risk of GBS was fourfold higher after acute respiratory tract infection (IRR, 3.89; 95% CI, 3.52-4.30; p < 0.0001) or gastrointestinal infection (IRR, 3.64; 95% CI, 3.01-4.40; p < 0.0001).

CONCLUSIONS

No association between seasonal influenza vaccination and GBS was shown during the 42 days following vaccination.

Bioactive Glass in a Rare Case of Osteomyelitis of the Heel in a Guillain-Barré Syndrome: A Case Report

Guillain-Barré syndrome (GBS) represents an acute inflammatory immune-mediated demyelinating polyradiculoneuropathy with an incidence of 0.6 per 100 000 people. In this article, we report the case of a 19-year-old girl affected by GBS since the age of 2 who presented at our clinic complaining for a chronic plantar hindfoot–infected ulceration. Serology showed increase of inflammatory markers and leukocytosis, and magnetic resonance imaging revealed osteomyelitis of calcaneum and soft tissue alterations with air bubbles. The patient was treated in our clinic by an integrated multidisciplinary approach consisting of immediate admission, soft tissue and bone debridement, and administration of antibiotics under the close control of infectious disease specialist. After the control of acute condition, the patient underwent negative pressure therapy associated with instillation of antiseptic solution until the restoration of bone and soft tissue loss of substance and, eventually, to the application of bioactive glass substitute until the achievement of complete wound healing.

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.

Vaccines and the risk of Guillain-Barré syndrome

The role of vaccination in the development of Guillain-Barré syndrome (GBS) is controversial, although cases of GBS have been reported following a wide range of vaccines. A nested case-control study was conducted between January 2011 and December 2015 in three Chinese cities. Four controls were matched to a case by gender, age, address and index date. An independent expert committee validated the diagnoses of cases and controls according to the Brighton Collaboration GBS case definition. Data on vaccinations were obtained from computerized vaccination records. Causal relations were assessed by conditional logistic regression. 1056 cases of GBS and 4312 controls were included in the analyses. Among paediatric and adult population, adjusted ORs for GBS occurrence within 180 days following vaccination were 0.94 (95% CI 0.54-1.62) and 1.09 (95% CI 0.88-1.32), respectively. No increased risk of GBS was detected for vaccination against hepatitis B, influenza, hepatitis A, varicella, rabies, polio(live), diphtheria, pertuss(acellular), tetanusis, measles, mumps, rubella, Japanese Encephalitis, and meningitis vaccines. Adjusted ORs for the recurrence of GBS after vaccination among paediatric and adult population were 0.85 (95% CI 0.07-9.50) and 1.18 (95% CI 0.49-2.65), respectively. In this large retrospective study, we did not find evidence of an increased risk of GBS and its recurrence among either paediatric (≤ 18 years) or adult (> 18 years) individuals within the 180 days following vaccinations of any kind, including influenza vaccination.

Should rare immunologic, neurologic, and other adverse events be indications to withhold vaccination?

Millions of illnesses, hospitalizations, and deaths are prevented by vaccination worldwide. This discussion examines vaccine safety concerns from the past several decades of immunization research. Both immunologic and non-immunologic side effects are reviewed, and clarification is provided regarding some highly-publicized myths regarding vaccine safety.

Impact of H1N1 Influenza Vaccination on Child Morbidity in Guinea-Bissau

BACKGROUND

In addition to vaccines' specific effects, vaccines may have non-specific effects (NSEs) altering the susceptibility to unrelated infections. Non-live vaccines have been associated with negative NSEs. In 2010, a campaign with the non-live H1N1-influenza vaccine targeted children 6-59 months in Guinea-Bissau.

METHODS

Bandim Health Project runs a health and demographic surveillance system site in Guinea-Bissau. Using a Cox proportional hazards model, we compared all-cause consultation rates after vs. before the campaign, stratified by participation status.

RESULTS

Among 10 290 children eligible for the campaign, 60% had participated, 18% had not and for 22% no information was obtained. After the H1N1 campaign, the consultation rates tended to decline less for participants [HR = 0.80 (95% confidence interval, CI: 0.75; 0.85)] than for non-participants [HR = 0.68 (95% CI: 0.58; 0.79)], p = 0.06 for same effect.

CONCLUSION

The decline in the vaccinated group may have been smaller than the decline in the non-vaccinated group consistent with H1N1-vaccine increasing susceptibility to unrelated infections.

Surveillance for Guillain-Barré syndrome after 2015-2016 and 2016-2017 influenza vaccination of Medicare beneficiaries

BACKGROUND

Guillain-Barré syndrome (GBS) is a serious acute demyelinating disease, an increased risk of which was found after the 1976 swine flu vaccinations. The U.S. Food and Drug Administration, in collaboration with the Centers for Medicare & Medicaid Services, has been conducting active surveillance for GBS after influenza vaccinations of Medicare Fee-For-Service beneficiaries since 2009.

METHODS

We conducted active surveillance for GBS claims in the 2015-2016 and 2016-2017 influenza seasons using the Updating Sequential Probability Ratio Test (USPRT) to monitor for signals of GBS risk. We performed self-controlled risk interval (SCRI) analyses at the end of both seasons, including chart confirmation in the 2015-2016 season, to estimate the odds ratio of GBS risk. We used 1-42 and 8-21 days post-vaccination as primary and secondary risk windows, respectively, and 43-84 days post-vaccination as the control window.

RESULTS

Over 13 million beneficiaries were vaccinated in each season. USPRT found a low magnitude signal for GBS in both seasons. SCRI analyses did not find excess GBS risk following any influenza vaccine for days 1-42 post-vaccination in either season. In the 2015-2016 season, for the 8-21 day window, our chart-confirmation showed an attributable GBS risk of 0.87 (95% CI: 0.16, 1.49) and 1.68 (95% CI: 0.69, 2.41) cases per million vaccinees after all seasonal and high dose (HD) vaccines, respectively, an elevated GBS risk for beneficiaries aged ≥75 years following all seasonal vaccines (OR: 2.25; 95% CI: 1.15, 4.39) and HD vaccine (OR: 3.67, 95% CI: 1.52, 8.85), and an elevated GBS risk for males who received seasonal vaccines (OR: 2.18; 95% CI: 1.15, 4.15) and HD vaccine (OR: 3.33; 95% CI: 1.35, 8.20). The finding of elevated GBS risk with advancing age and in males is consistent with literature; however, a distinction between HD and SD was a new finding. In the 2016-17 season, for the 8-21 day window, attributed cases showed an attributable GBS risk of 0.87 (95% CI: 0.03, 1.61) and 1.11 (95% CI: 0.00, 2.01) cases per million vaccinees after all seasonal and HD vaccines, respectively. We found no excess GBS risk for standard dose vaccines in the 8-21 day window in either season.

CONCLUSIONS

Our primary analysis finding of no excess GBS risk during both seasons was reassuring. The slightly elevated GBS risk, although in the expected range, in the 8-21 day window after all seasonal and high dose vaccines, but not after standard dose vaccines is hypothesis-generating because the difference may be due to vaccine factors such as antigen amount or strains in various seasons or due to host factors.

Clinical and electrophysiological characteristics of Guillain-Barré syndrome in Colombia

Despite the wide literature describing the features of Guillain-Barré syndrome (GBS) in different populations worldwide, Colombian data are very scarce. We aim to characterize patients with GBS in a general hospital setting in Colombia. We conducted a retrospective chart review of GBS cases managed at the Hospital Universitario Fundación Santa Fe de Bogotá, from 2011 to 2016. Twenty-three patients were included. The most commonly reported symptoms were paresthesias (65%), pain (61%), proximal (22%) and distal (74%) limb weakness, and facial palsy (30%). 9% of patients had Fisher syndrome and 21% had other variants: Bickerstaff, pharyngeal-cervical-brachial pattern, and facial diplegia. There was a predominance of the demyelinating form (70%), with only 22% of patients presenting with the axonal variants. Our results are concordant with previous studies in Colombia.

Guillain-Barré syndrome and influenza vaccines: current evidence

OBJECTIVE

Guillain-Barré Syndrome (GBS) as a consequence of influenza vaccination is a relevant topic, yet to be clarified, which raises concern both amongst health care personnel and the general population. Every study and pharmacovigilance system point to need of further research and the importance of continuous monitoring of safety regarding influenza vaccines. The aim of the present study is to investigate the publication of new data since the realisation of our meta-analysis of GBS and influenza vaccines (published in 2015).

METHODS

A systematic revision of PubMed, Embase, and Web of Knowledge (WOS) databases has been carried out. These report observational studies assessing GBS risk after the administration of influenza vaccines from May 2014 up to July 20th, 2017.

RESULTS

The research yielded 107 articles. Only three studies met established inclusion criteria and referred to an estimation GBS risk after some influenza vaccine. Two studies investigated GBS risk by the pandemic A/H1N1 vaccine, while only one looked into season vaccines.

CONCLUSIONS

The present systematic review, conducted after the publication of our previous meta-analysis, seems to confirm its previous results. Therefore, GBS should be considered an infrequent adverse effect of influenza vaccination, which should not negatively influence its acceptance. Unfortunately, very few of the systematically surveyed studies meeting inclusion criteria. This fact sharply contrasts with the current consensus as to the need of continuously monitoring the safety of influenza vaccines.

A simulation study of the statistical power and signaling characteristics of an early season sequential test for influenza vaccine safety

PURPOSE

The US Food and Drug Administration monitors the risk of Guillain-Barré syndrome (GBS) following influenza vaccination using several data sources including Medicare. In the 2017 to 2018 season, we transitioned our near real-time surveillance in Medicare to more effectively detect large GBS risk increases early in the season while avoiding false positives.

METHODS

We conducted a simulation study examining the ability of the updating sequential probability ratio test (USPRT) to detect substantially elevated GBS risk in the 8- to 21-day postvaccination versus 5× to 30× the historical rate. We varied the first testing week (weeks 5-8) and the null rate (1×-3×) and evaluated power. We estimated signal probability and the risk ratio (RR) after signaling when high-risk seasons were rare.

RESULTS

Applying fixed alternatives, we found >80% power to detect a risk 30× the historical rate in week 5 for the 1× null and in week 6 for the 1.5× to 3× nulls. Nearly all testing schedules had >80% power for a 5× risk by week 11. To test the robustness of USPRT, we further simulated seasons where 1% were true high-risk seasons. Using a 1× null led to 10% of seasons signaling by week 11 (median RR approximately 1.4), which decreased to approximately 1% with the ≥2.5× null (median RR approximately 16.0).

CONCLUSIONS

On the basis of the results from this simulation and subsequent consultations with experts and stakeholders, we specified USPRT to test continuously from weeks 7 to 11 using the null hypothesis that the observed GBS rate was 2.5× the historical rate. This helped improve the ability of USPRT to provide early detection of GBS risk following influenza vaccination as part of a multilayered system of surveillance.

Surveillance for Guillain-Barré syndrome after influenza vaccination among U.S. Medicare beneficiaries during the 2017-2018 season

BACKGROUND

The U.S. Food and Drug Administration and the Centers for Medicare & Medicaid Services have been actively monitoring the risk of Guillain-Barré syndrome (GBS) following influenza vaccination among Fee-for-Service (FFS) Medicare beneficiaries every season since 2008. We present our evaluation of the GBS risk following influenza vaccinations during the 2017-2018 season.

METHODS

We implemented a multilayered approach to active safety surveillance that included near real-time surveillance early in the season, comparing GBS rates post-vaccination during the 2017-2018 season with rates from five prior seasons using the Updating Sequential Probability Ratio Test (USPRT), and end-of-season self-controlled risk interval (SCRI) analyses.

RESULTS

We identified approximately 16 million influenza vaccinations. The near real-time surveillance did not signal for a potential 2.5-fold increased GBS risk either in days 8-21 or 1-42 post-influenza vaccination. In the SCRI analyses, we did not detect statistically significant increased GBS risks among influenza-vaccinated Medicare beneficiaries ≥65 years for either the 8-21 or 1-42-day risk windows for all seasonal vaccines combined, high-dose vaccine, or standard-dose vaccines; we did detect an increased GBS risk in days 8-21 post-vaccination for individuals vaccinated with the adjuvanted vaccine (OR: 3.75; 95% CI: 1.01, 13.96), although this finding was not statistically significant after multiplicity adjustment (p = 0.146).

CONCLUSIONS

Our multilayered surveillance approach-which allows for early detection of elevated GBS risk and provides reliable end-of-season SCRI estimates of effect size-did not identify an increased GBS risk following 2017-2018 influenza vaccinations. The slightly increased GBS risk with the adjuvanted vaccine, which was not statistically significant following multiplicity adjustment, is consistent with the package inserts of all U.S.-licensed influenza vaccines, which warn of a potential low increased GBS risk. The benefits of influenza vaccines in preventing morbidity and mortality heavily outweigh this potential risk.

Eventos adversos pós-vacinação contra influenza em idosos no Brasil

Objetivo Identificar e analisar a ocorrência de eventos adversos pós vacinação contra Influenza em idosos brasileiros.Método Pesquisa descritiva, analítica, retrospectiva e quantitativa. Participaram desta pesquisa 98 idosos identificados por meio das fichas de notificação de eventos adversos pós vacinação disponibilizados pelo Sistema de Informação de Eventos Adversos Pós Vacinação de Minas Gerias - BR, entre 2014 e 2016. Os dados foram duplamente digitados e transportados para os programas Ri386 versão 3.4.3 3 IBM SPSS Statics versão 25. Realizou-se estatísticas descritivas, frequência e percentual para as variáveis qualitativas e medidas de tendência central (média e mediana) e dispersão (desvio padrão) para as variáveis numéricas. Para verificar a associação entre os tipos de eventos (não grave, grave e erro de imunização) e as manifestações sistêmicas com as variáveis de caracterização dos idosos e das vacinas, utilizou-se o teste Exato de Fisher e Qui-quadrado; o nível de significância utilizado foi p<=0,05.Resultados Dos idosos estudados, 75,5% eram do sexo feminino com predominância da raça branca (55,1%) cuja idade variou entre 60 e 97 anos; 84,7% dos eventos adversos foram descritos como Evento Adverso Não Grave, com 64,3% de manifestações locais e 27,6% de manifestações sistêmicas.Conclusão Proporcionar informações específicas aos enfermeiros no que tange os cuidados pré e pós vacinação contra Influenza é de fundamental importância para o estabelecimento de atendimento adequado livre de danos aos idosos e que não incorra em eventos adversos evitáveis.

Active surveillance for safety monitoring of seasonal influenza vaccines in Italy, 2015/2016 season

BACKGROUND

Surveillance for adverse events following immunization is an important component of any national immunization programme because it is critical to assessing the safety of vaccines and to detecting potentially rare and severe adverse events and responding in a timely manner. We conducted an enhanced active surveillance aimed at assessing the safety of flu vaccines in the 2015-2016 season in Italy. The study was targeted to the population groups for which the seasonal vaccine is recommended in Italy.

METHODS

During the study period, a total of 3213 individuals receiving seasonal influenza vaccination were registered on the web-based platform. Any adverse events experienced after 7 days from vaccination by individuals aged six months or more were collected through a telephone interview or by a web-based self-administered questionnaire. All individuals experiencing at least one event during the 7 days of follow-up were contacted for follow-up to 60 days.

RESULTS

Overall, 854 events were reported: 845 events (26%) after administration of the first dose and 9 (12%) after the second dose. The majority of adverse events reported after 7 days from the first dose were of little clinical importance, and most involved local symptoms.

CONCLUSION

Our data, even though the number of vaccinated individuals was smaller than expected, is consistent with the safety of influenza vaccines in Italy during the 2015-2016 season regarding the most common adverse events. Further efforts are needed to obtain sufficient power to study rarer adverse events. Active monitoring and systematic studies to test generated signals and hypotheses are crucial to intensify awareness among the public and professionals with regard to the safety of vaccines.

Systematic review of factors associated with the development of Guillain-Barré syndrome 2007-2017: what has changed?

OBJECTIVE

The objective of this study was to describe the factors associated with the development of Guillain-Barré syndrome, both infectious and non-infectious, during and after the A(H1N1) influenza pandemic in 2009 and the recent Zika virus epidemic in the Americas.

METHOD

Systematic review of literature on factors associated with the development of the Guillain-Barré syndrome published between 2007 and 2017 listed in EBSCO, MEDLINE and LILACS databases. The quality of the studies was evaluated using the Newcastle Ottawa Scale.

RESULTS

Thirty-four articles met inclusion criteria and were selected for analysis. Their quality was considered good in relation to most of the items evaluated. Many aetiological agents had the results of association with Guillain-Barré syndrome, among them Campylobacter jejuni, influenza vaccine - both pandemic and seasonal vaccines, respiratory infection, gastrointestinal infection among others. The aetiological agents found are, in most part, the same reported prior to the study period. The association with surgeries, chikungunya virus (CHIKV), Zika virus and quadrivalent human papillomavirus vaccine stand out as new aetiological agents in the list of the various possible agents that trigger Guillain-Barré syndrome reported in the study period. There were no Brazilian studies identified during this period.

CONCLUSIONS

The results of the review reaffirmed C. jejuni as the major trigger of GBS, whereas the association of influenza vaccines and GBS is less clear; Zika virus infection in association with GBS was found in only one study.

Clinical and laboratory findings of patients with the possible diagnosis of influenza hospitalized in affiliated hospitals of Babol University of Medical Sciences, 2015-2016

The clinical and para clinical manifestations of influenza in various patients have range from an autoimmune disease to a life-threatening respiratory infection. In addition, the severity of the disease is influenced by factors such as demographic factors, underlying diseases, and immune response. Therefore, in this study, we evaluated the clinical, laboratory and epidemiological characteristics of patients with this type of influenza in Babol (north of Iran). This study was conducted as a descriptive cross-sectional study from October 2015 to March 2016. Subsequently, in this study, records of 123 patients with clinical signs of the influenza-like disease who have undergone the clinical sign in hospitals affiliated to Babol University of Medical Sciences were reviewed. Of 123 patients admitted to a possible diagnosis of influenza, 58 patients (47.2%) were PCR positive for H1N1, while seventy nine (64.2%) participants were women and 21 (17.1%) had diabetes or underlying lung disease. Most of the involved age groups were of individuals above the age of 50. These were followed by the 21-35 years-old. Fever (78%), cough (65.9%), shivering (58.5%) and myalgia (56.1%) were the most common clinical symptoms. Increased levels of transaminases (43.1%), leukocytosis (35.8%) and thrombocytopenia (34.2%) were as well reported in patients as the most frequently reported para clinical findings. In the present study, the most usual clinical symptoms were fever, cough, chill, and myalgia, while gastrointestinal symptoms were also noticeably observed in patients. In an experimental study, a significant number of patients showed leukocytosis and thrombocytopenia and increased transaminases.

Vaccine-preventable diseases, vaccines and Guillain-Barre' syndrome

Guillain-Barré syndrome (GBS) is an acute, immune-mediated polyradiculoneuropathy. Infections and vaccines have been hypothesized to play a role in triggering GBS development. These beliefs can play a role in reducing vaccination coverage. In this report, data concerning this hypothesis are discussed. It is shown that an association between vaccine administration and GBS has never been proven for most of debated vaccines, although it cannot be definitively excluded. The only exception is the influenza vaccine, at least for the preparation used in 1976. For some vaccines, such as measles/mumps/rubella, human papillomavirus, tetravalent conjugated meningococcal vaccine, and influenza, the debate between supporters and opponents of vaccination remains robust and perception of vaccines' low safety remains a barrier to achieving adequate vaccination coverage. Less than 1 case of GBS per million immunized persons might occur for these vaccines. However, in some casesimmunization actually reduces the risk of GBS development. In addition, the benefits of vaccination are clearly demonstrated by the eradication or enormous decline in the incidence of many vaccine-preventable diseases. These data highlight that the hypothesized risks of adverse events, such as GBS, cannot be considered a valid reason to avoid the administration of currently recommended vaccines.

Influenza vaccines: Evaluation of the safety profile

The safety of vaccines is a critical factor in maintaining public trust in national vaccination programs. Vaccines are recommended for children, adults and elderly subjects and have to meet higher safety standards, since they are administered to healthy subjects, mainly healthy children. Although vaccines are strictly monitored before authorization, the possibility of adverse events and/or rare adverse events cannot be totally eliminated. Two main types of influenza vaccines are currently available: parenteral inactivated influenza vaccines and intranasal live attenuated vaccines. Both display a good safety profile in adults and children. However, they can cause adverse events and/or rare adverse events, some of which are more prevalent in children, while others with a higher prevalence in adults. The aim of this review is to provide an overview of influenza vaccine safety according to target groups, vaccine types and production methods.

Epilepsy in Children After Pandemic Influenza Vaccination

OBJECTIVES

To determine if pandemic influenza vaccination was associated with an increased risk of epilepsy in children.

METHODS

Information from Norwegian registries from 2006 through 2014 on all children <18 years living in Norway on October 1, 2009 was used in Cox regression models to estimate hazard ratios for incident epilepsy after vaccination. A self-controlled case series analysis was used to estimate incidence rate ratios in defined risk periods after pandemic vaccination.

RESULTS

In Norway, the main period of the influenza A subtype H1N1 pandemic was from October 2009 to December 2009. On October 1, 2009, 1 154 113 children <18 years of age were registered as residents in Norway. Of these, 572 875 (50.7%) were vaccinated against pandemic influenza. From October 2009 through 2014 there were 3628 new cases of epilepsy (incidence rate 6.09 per 10 000 person-years). The risk of epilepsy was not increased after vaccination: hazard ratio: 1.07; 95% confidence interval: 0.94-1.23. Results from the self-controlled case series analysis supported the finding of no association between vaccination and subsequent epilepsy.

CONCLUSIONS

Pandemic influenza vaccination was not associated with increased risk of epilepsy. Concerns about pandemic vaccination causing epilepsy in children seem to be unwarranted.

Risk of Guillain-Barré Syndrome following quadrivalent human papillomavirus vaccine in the Vaccine Safety Datalink

OBJECTIVE

Describe the Vaccine Safety Datalink's (VSD) Guillain Barré Syndrome (GBS) surveillance following quadrivalent HPV vaccine (4vHPV) from 2006 through 2015.

METHODS

Among 4vHPV vaccinated persons aged 9-26, ICD-9 coded GBS was identified in VSD's electronic data. Medical records were reviewed and adjudicated to confirm GBS. We calculated incidence rates of confirmed GBS within 1-42days following 4vHPV with a one-sided 95% confidence interval.

RESULTS

Following 2,773,185 4vHPV doses, we confirmed 1 case of GBS in a male and no cases among females. The incidence rate of medical record confirmed GBS within 42days following 4vHPV vaccine was 0.36 cases per million 4vHPV doses administered (1-sided 95% CI 1.71), which was less than the background rate.

CONCLUSION

We found no evidence of an increased risk of GBS following 4vHPV. With an upper 95% confidence limit, we estimate that, if an increased risk exists, we would expect at most 1.08 additional cases of GBS per million people vaccinated with 4vHPV.

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.

Clinical Features of Post-Vaccination Guillain-Barré Syndrome (GBS) in Korea

Guillain-Barré syndrome (GBS) is the most common immune-mediated polyradiculoneuropathy and it is also the most commonly reported severe adverse event following immunization in adults. To evaluate the results of clinical and laboratory features of GBS after vaccination in Korea, we analyzed the claims-based data from 2002 to 2014 using materials collected for the Advisory Committee Vaccination Injury Compensation (ACVIC) meeting including, clinical features, nerve conduction studies (NCSs), cerebrospinal fluid (CSF) profiles, treatment, and outcomes. Forty-eight compensated GBS cases (median age, 15 years; interquartile range [IQR], 13-51; male:female ratio, 1:1) of 68 suspected GBS were found following immunization and all of them with influenza immunizations with either monovalent (n = 35) or trivalent (n = 13). Among them, 30 cases fulfilled the Brighton criteria level 1-3 (62.5%). The median duration between the onset of symptoms to nadir, duration of the nadir, and total admission period were 3 (IQR, 2-7 days), 2 (IQR, 1-5 days), and 14 (IQR, 6-33 days) days, respectively. The most frequently reported symptom was quadriparesis which was present in 36 cases (75%) at nadir. CSF examination revealed albuminocytologic dissociation in 25.0% and NCS was abnormal in 61.8%. After treatment, most of them showed improvement. Clinical features were similar to typical post-infectious GBS and there were both demyelinating and axonal forms suggesting heterogeneous pathogenic mechanism. In order to improve the diagnostic certainty of post-vaccination GBS, careful documentation of clinical features and timely diagnostic work-up with follow-up studies are needed.

Guillain-Barré Syndrome in Pregnancy

Guillain-Barré syndrome has been reported in pregnancy and is a potentially lethal condition. It affects the nervous system with acute onset of symmetric ascending weakness and may result in frank respiratory failure and autonomic dysfunction. Most patients recall symptoms of a respiratory or gastrointestinal illness in the weeks preceding the onset of weakness. Recent evidence suggests a potential role of the Zika virus as a trigger for the syndrome. The diagnosis of Guillain-Barré is clinical. Supportive measures include venous thromboembolism prophylaxis, aggressive physical therapy, pressure ulcer prevention, enteral nutrition, and respiratory support. The mainstay of management comprises plasmapheresis or administration of intravenous immunoglobulins. Affected patients must be closely monitored for development of respiratory failure and autonomic dysfunction. Treatment during pregnancy should follow the same principles as for nonpregnant individuals.

Guillain-Barré Syndrome

Guillain-Barré syndrome is an acute inflammatory immune-mediated polyradiculoneuropathy presenting typically with tingling, progressive weakness, and pain. Variants and formes frustes may complicate recognition. The best known variant is the sensory ataxic form of Miller Fisher syndrome, which also affects the oculomotor nerves and the brain stem. Divergent pathologic mechanisms lead to demyelinating, axonal, or mixed demyelinating-axonal damage. In the demyelinating form, yet to be identified antigens are inferred by complement activation, myelin destruction, and macrophage-activated cleanup. In the axonal and Miller Fisher variants, gangliosides (GM1, GD1a, GQ1b) are targeted by immunoglobulins and share antigenic epitopes with some bacterial and viral antigens. Campylobacter jejuni infection is associated with an axonal-onset variant; affected patients commonly experience more rapid deterioration. Many other antecedent infectious agents have been recognized including the most recently identified, Zika virus. Supportive care remains the mainstay of therapy. Plasma exchange or intravenous immunoglobin hastens recovery. Combination immunotherapy is not more effective, and the efficacy of prolonged immunotherapy is unproven. One in 3 patients will have deterioration severe enough to require prolonged intensive care monitoring or mechanical ventilation. Full recovery is often seen; most patients regain ambulation, even in severe cases, but disability remains in up to 10% and perhaps more. Numerous challenges remain including early identification and control of infectious triggers, improved access of modern neurointensive care worldwide, and translating our understanding of pathogenesis into meaningful preventive or assistive therapies. This review provides a historical perspective at the centenary of the first description of the syndrome, insights into its pathogenesis, triage, initial immunotherapy, and management in the intensive care unit.

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.

The safety of influenza vaccines in children: An Institute for Vaccine Safety white paper

Most influenza vaccines are generally safe, but influenza vaccines can cause rare serious adverse events. Some adverse events, such as fever and febrile seizures, are more common in children than adults. There can be differences in the safety of vaccines in different populations due to underlying differences in genetic predisposition to the adverse event. Live attenuated vaccines have not been studied adequately in children under 2 years of age to determine the risks of adverse events; more studies are needed to address this and several other priority safety issues with all influenza vaccines in children. All vaccines intended for use in children require safety testing in the target age group, especially in young children. Safety of one influenza vaccine in children should not be extrapolated to assumed safety of all influenza vaccines in children. The low rates of adverse events from influenza vaccines should not be a deterrent to the use of influenza vaccines because of the overwhelming evidence of the burden of disease due to influenza in children.

Prevention and Control of Seasonal Influenza with Vaccines

This report updates the 2015-16 recommendations of the Advisory Committee on Immunization Practices (ACIP) regarding the use of seasonal influenza vaccines (Grohskopf LA, Sokolow LZ, Olsen SJ, Bresee JS, Broder KR, Karron RA. Prevention and control of influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices, United States, 2015-16 influenza season. MMWR Morb Mortal Wkly Rep 2015;64:818-25). Routine annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. For the 2016-17 influenza season, inactivated influenza vaccines (IIVs) will be available in both trivalent (IIV3) and quadrivalent (IIV4) formulations. Recombinant influenza vaccine (RIV) will be available in a trivalent formulation (RIV3). In light of concerns regarding low effectiveness against influenza A(H1N1)pdm09 in the United States during the 2013-14 and 2015-16 seasons, for the 2016-17 season, ACIP makes the interim recommendation that live attenuated influenza vaccine (LAIV4) should not be used. Vaccine virus strains included in the 2016-17 U.S. trivalent influenza vaccines will be an A/California/7/2009 (H1N1)-like virus, an A/Hong Kong/4801/2014 (H3N2)-like virus, and a B/Brisbane/60/2008-like virus (Victoria lineage). Quadrivalent vaccines will include an additional influenza B virus strain, a B/Phuket/3073/2013-like virus (Yamagata lineage).Recommendations for use of different vaccine types and specific populations are discussed. A licensed, age-appropriate vaccine should be used. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended product is otherwise appropriate. This information is intended for vaccination providers, immunization program personnel, and public health personnel. Information in this report reflects discussions during public meetings of ACIP held on October 21, 2015; February 24, 2016; and June 22, 2016. These recommendations apply to all licensed influenza vaccines used within Food and Drug Administration-licensed indications, including those licensed after the publication date of this report. Updates and other information are available at CDC's influenza website (http://www.cdc.gov/flu). Vaccination and health care providers should check CDC's influenza website periodically for additional information.

Guillain-Barré syndrome

Guillain-Barré syndrome is the most common and most severe acute paralytic neuropathy, with about 100,000 people developing the disorder every year worldwide. Under the umbrella term of Guillain-Barré syndrome are several recognisable variants with distinct clinical and pathological features. The severe, generalised manifestation of Guillain-Barré syndrome with respiratory failure affects 20-30% of cases. Treatment with intravenous immunoglobulin or plasma exchange is the optimal management approach, alongside supportive care. Understanding of the infectious triggers and immunological and pathological mechanisms has advanced substantially in the past 10 years, and is guiding clinical trials investigating new treatments. Investigators of large, worldwide, collaborative studies of the spectrum of Guillain-Barré syndrome are accruing data for clinical and biological databases to inform the development of outcome predictors and disease biomarkers. Such studies are transforming the clinical and scientific landscape of acute autoimmune neuropathies.

Adverse events following pandemic influenza A (H1N1) 2009 monovalent and seasonal influenza vaccinations during the 2009-2010 season in the active component U.S. military and civilians aged 17-44years reported to the Vaccine Adverse Event Reporting System

BACKGROUND

No comparative review of Vaccine Adverse Event Reporting System (VAERS) submissions following pandemic influenza A (H1N1) 2009 and seasonal influenza vaccinations during the pandemic season among U.S. military personnel has been published.

METHODS

We compared military vs. civilian adverse event reporting rates. Adverse events (AEs) following vaccination were identified from VAERS for adults aged 17-44years after pandemic (monovalent influenza [MIV], and seasonal (trivalent inactivated influenza [IIV3], live attenuated influenza [LAIV3]) vaccines. Military vaccination coverage was provided by the Department of Defense's Defense Medical Surveillance System. Civilian vaccination coverage was estimated using data from the National 2009 H1N1 Flu Survey and the Behavioral Risk Factor Surveillance System survey.

RESULTS

Vaccination coverage was more than four times higher for MIV and more than twenty times higher for LAIV3 in the military than in the civilian population. The reporting rate of serious AE reports following MIV in service personnel (1.19 per 100,000) was about half that reported by the civilian population (2.45 per 100,000). Conversely, the rate of serious AE reports following LAIV3 among service personnel (1.32 per 100,000) was more than twice that of the civilian population. Although fewer military AEs following MIV were reported overall, the rate of Guillain-Barré Syndrome (GBS) (4.01 per million) was four times greater than that in the civilian population. (1.04 per million).

CONCLUSIONS

Despite higher vaccination coverage in service personnel, the rate of serious AEs following MIV was about half that in civilians. The rate of GBS reported following MIV was higher in the military.