AS03 adjuvanted AH1N1 vaccine associated with an abrupt increase in the incidence of childhood narcolepsy in Finland

Incidence of narcolepsy symptoms after taking COVID-19 vaccines: a Jordanian cross-sectional study

Purpose

Sleeping disorders were reported in many patients who took vaccines during previous pandemics. We aim to investigate the relationship between coronavirus disease 2019 (COVID-19) vaccines and the incidence of narcolepsy symptoms in the Jordanian population.

Materials and Methods

We used a descriptive, cross-sectional, online self-administered survey conducted between December 2022 and May 2023. The survey targeted males and females above the age of 18 years who took any type of COVID-19 vaccine, had no chronic diseases, and had no sleep disorders prior to taking the vaccine. The survey was distributed via social media platforms.

Results

A total of 873 participants were included in this study, consisting of 44.4% males and 55.6% females, with the majority being in the 18-29 age group. Most participants (79.8%) received two vaccine doses, with the Pfizer vaccine being the most common. Nearly half of the participants reported excessive daytime sleepiness. Sleep paralysis and hypnagogic hallucinations were reported by a notable proportion of participants, but no significant differences were found among the vaccine types. Sleep attacks and fragmented nighttime sleep were associated with the number of vaccine doses received, suggesting a possible influence of the dose count on these symptoms. The presence of excessive daytime sleepiness, sudden loss of muscle tone, sleep paralysis, and hypnagogic hallucinations showed no significant association with the number of doses taken.

Conclusion

We hypothesize a possible link between COVID-19 vaccination and the emergence of narcolepsy symptoms in Jordanian individuals. Additional investigations and continuous monitoring to determine the extent of the risk and uncover potential mechanisms behind this connection should be performed.

Cell-based vs enzyme-linked immunosorbent assay for detection of anti-Tribbles homolog 2 autoantibodies in Chinese patients with narcolepsy

STUDY OBJECTIVES

Narcolepsy type 1 is attributed to a deficiency in cerebrospinal fluid orexin and is considered linked to autoimmunity. The levels of anti-Tribbles homolog 2 (TRIB2) autoantibodies are elevated in the sera of some patients with narcolepsy with cataplexy. Additionally, injecting mice with serum immunoglobulin from patients with narcolepsy with positive anti-TRIB2 antibodies can induce hypothalamic neuron loss and alterations in sleep patterns. Consequently, we hypothesized the existence of a potential association between anti-TRIB2 antibodies and narcolepsy. To test this possibility, we used cell-based assays (CBAs) and enzyme-linked immunosorbent assays (ELISAs) to detect the presence of anti-TRIB2 antibodies in Chinese patients with narcolepsy.

METHODS

We included 68 patients with narcolepsy type 1, 39 patients with other central disorders of hypersomnolence, and 43 healthy controls. A CBA and a conventional ELISA were used to detect anti-TRIB2 antibody levels in patients' sera.

RESULTS

CBA was used to detect serum anti-TRIB2 antibodies in Chinese patients with narcolepsy, and the results were negative. However, when the ELISA was used, only 2 patients with narcolepsy type 1 had TRIB2 antibody titers higher than the mean titer plus 2 standard deviations of the healthy controls.

CONCLUSIONS

In our study, ELISA identified TRIB2 autoantibodies in sera of patients with narcolepsy where CBA failed to demonstrate them. Contrary to our hypothesis, this intriguing finding deserves further research to elucidate the potential association between TRIB2 and narcolepsy type 1. Exploring the implications of TRIB2 autoantibodies in narcolepsy and disparate outcomes between ELISA and CBA could provide crucial insights.

CITATION

Zhong X, Yuan Y, Zhan Q, et al. Cell-based vs enzyme-linked immunosorbent assay for detection of anti-Tribbles homolog 2 autoantibodies in Chinese patients with narcolepsy. J Clin Sleep Med. 2024;20(6):941-946.

Homozygous HLA-DQB1*06:02 combined with T-cell receptor alpha polymorphism results in narcolepsy onset - A familial case report

Narcolepsy is a life-long neurological disorder with well-established genetic risk factors. Human leukocyte antigen-DQB1*06:02 remains the strongest genetic predeterminant; however, polymorphisms in genes encoding the T-cell receptor alpha chain are also strongly linked. This case report shows the inheritance pathway of these genetic markers contributing to narcolepsy onset in a 17-year-old female.

COVID-19 Vaccination Strategies in the Endemic Period: Lessons from Influenza

Coronavirus disease 2019 (COVID-19) is a highly contagious zoonotic respiratory disease with many similarities to influenza. Effective vaccines are available for both; however, rapid viral evolution and waning immunity make them virtually impossible to eradicate with vaccines. Thus, the practical goal of vaccination is to reduce the incidence of serious illnesses and death. Three years after the introduction of COVID-19 vaccines, the optimal vaccination strategy in the endemic period remains elusive, and health authorities worldwide have begun to adopt various approaches. Herein, we propose a COVID-19 vaccination strategy based on the data available until early 2024 and discuss aspects that require further clarification for better decision making. Drawing from comparisons between COVID-19 and influenza vaccination strategies, our proposed COVID-19 vaccination strategy prioritizes high-risk groups, emphasizes seasonal administration aligned with influenza vaccination campaigns, and advocates the co-administration with influenza vaccines to increase coverage.

Downregulation of hypocretin/orexin after H1N1 Pandemrix vaccination of adolescent mice

Narcolepsy type 1 (NT1), characterized by the loss of hypocretin/orexin (HCRT) production in the lateral hypothalamus, has been linked to Pandemrix vaccination during the 2009 H1N1 pandemic, especially in children and adolescents. It is still unknown why this vaccination increased the risk of developing NT1. This study investigated the effects of Pandemrix vaccination during adolescence on Hcrt mRNA expression in mice. Mice received a primary vaccination (50 µL i.m.) during prepubescence and a booster vaccination during peri-adolescence. Hcrt expression was measured at three-time points after the vaccinations. Control groups included both a saline group and an undisturbed group of mice. Hcrt expression was decreased after both Pandemrix and saline injections, but 21 days after the second injection, the saline group no longer showed decreased Hcrt expression, while the Pandemrix group still exhibited a significant reduction of about 60% compared to the undisturbed control group. This finding suggests that Pandemrix vaccination during adolescence influences Hcrt expression in mice into early adulthood. The Hcrt mRNA level did not reach the low levels known to induce NT1 symptoms, instead, our finding supports the multiple-hit hypothesis of NT1 that states that several insults to the HCRT system may be needed to induce NT1 and that Pandemrix could be one such insult.

Exploring exercise, physical wellbeing and the role of physiotherapy: perspectives from people with narcolepsy

Narcolepsy is associated with reduced quality of life and physical performance. The study aimed to explore the attitudes of people with Type 1 narcolepsy towards exercise and physical activity, their physical wellbeing, and the potential role of physiotherapy. Semi-structured interviews were conducted with 22 people with narcolepsy attending a dedicated outpatient narcolepsy clinic located in Dublin, Ireland. Transcripts were iteratively coded; a thematic analysis was undertaken, and key themes were identified. Four themes were identified: 'Barriers and Facilitators to Exercising', 'Social Concerns', 'Health Concerns' and 'Suggestions for the Role of Physiotherapy'. Future research should explore the potential role of exercise to help manage narcolepsy-related symptoms in this population.

Microstructural White Matter Abnormalities in Children and Adolescents With Narcolepsy Type 1

BACKGROUND

In 2010, the H1N1 Pandemrix vaccination campaign was followed by a sudden increase in narcolepsy type 1 (NT1). We investigated the brain white matter microstructure in children with onset of NT1 within two years after the Pandemrix vaccination.

METHODS

We performed diffusion-weighted magnetic resonance imaging (MRI) on 19 children and adolescents with NT1 and 19 healthy controls. Imaging was performed at a median of 4 years after the diagnosis at a median age of 16 years. For the MRI, we used whole-brain tractography and tract-based spatial statistics (TBSS). We compared these results with medical records and questionnaire data.

RESULTS

Narcoleptic children showed a global decrease in mean, axial, and radial diffusivity and an increase in planarity coefficient in the white matter TBSS skeleton and tractography. These differences were widespread, and there was an increased asymmetry of the mean diffusivity in children with NT1. The global microstructural metrics were reflected in behavior, and especially the axial diffusion levels correlated with anxiety and depression symptoms and social and behavioral problems.

CONCLUSIONS

In pediatric patients with Pandemrix-associated NT1, several global changes in the brain white matter network skeleton were observed within five years after the onset of NT1. The degree of changes correlates with behavioral problems.

Absence of specific autoantibodies in patients with narcolepsy type 1 as indicated by an unbiased random peptide-displayed phage screening

Narcolepsy type 1 (NT1) is an enigmatic sleep disorder characterized by the selective loss of neurons producing orexin (also named hypocretin) in the lateral hypothalamus. Although NT1 is believed to be an autoimmune disease, the orexinergic neuron-specific antigens targeted by the pathogenic immune response remain elusive. In this study, we evaluated the differential binding capacity of various peptides to serum immunoglobin G from patients with NT1 and other hypersomnolence complaints (OHCs). These peptides were selected using an unbiased phage display technology or based on their significant presence in the serum of NT1 patients as identified from previous studies. Although the subtractive biopanning strategy successfully enriched phage clones with high reactivity against NT1 serum IgG, the 101 randomly selected individual phage clones could not differentiate the sera from NT1 and OHC. Compared to the OHC control group, serum from several NT1 patients exhibited increased reactivity to the 12-mer peptides derived from TRBV7, BCL-6, NRXN1, RXRG, HCRT, and RTN4 proteins, although not statistically significant. Collectively, employing both unbiased and targeted methodologies, we were unable to detect the presence of specific autoantibodies in our NT1 patient cohort. This further supports the hypothesis that the autoimmune response in NT1 patients likely stems primarily from T cell-mediated immunity rather than humoral immunity.

Adjuvants in COVID-19 vaccines: innocent bystanders or culpable abettors for stirring up COVID-heart syndrome

COVID-19 infection is a multi-system clinical disorder that was associated with increased morbidity and mortality. Even though antiviral therapies such as Remdesvir offered modest efficacy in reducing the mortality and morbidity, they were not efficacious in reducing the risk of future infections. So, FDA approved COVID-19 vaccines which are widely administered in the general population worldwide. These COVID-19 vaccines offered a safety net against future infections and re-infections. Most of these vaccines contain inactivated virus or spike protein mRNA that are primarily responsible for inducing innate and adaptive immunity. These vaccines were also formulated to contain supplementary adjuvants that are beneficial in boosting the immune response. During the pandemic, clinicians all over the world witnessed an uprise in the incidence and prevalence of cardiovascular diseases (COVID-Heart Syndrome) in patients with and without cardiovascular risk factors. Clinical researchers were not certain about the underlying reason for the upsurge of cardiovascular disorders with some blaming them on COVID-19 infections while others blaming them on COVID-19 vaccines. Based on the literature review, we hypothesize that adjuvants included in the COVID-19 vaccines are the real culprits for causation of cardiovascular disorders. Operation of various pathological signaling events under the influence of these adjuvants including autoimmunity, bystander effect, direct toxicity, anti-phospholipid syndrome (APS), anaphylaxis, hypersensitivity, genetic susceptibility, epitope spreading, and anti-idiotypic antibodies were partially responsible for stirring up the onset of cardiovascular disorders. With these mechanisms in place, a minor contribution from COVID-19 virus itself cannot be ruled out. With that being said, we strongly advocate for careful selection of vaccine adjuvants included in COVID-19 vaccines so that future adverse cardiac disorders can be averted.

Vestibular disorders following BNT162b2 mRNA COVID-19 vaccination: A retrospective case series

BACKGROUND

There are few publications regarding manifestations of vestibular disorders (VDs) following BNT162b2 mRNA COVID-19 vaccination.

PURPOSE

We describe cases of VD potentially related to BNT162b2 vaccination and calculate its reporting rate, in order to enlarge knowledge about this adverse effect.

METHODS

A retrospective analysis of cases of VD following BNT162b2 vaccination reported to the pharmacovigilance centre of Georges-Pompidou European Hospital (France), in 2021 was performed. In order to identify these cases from the pharmacovigilance database containing all our registered cases, we used the Standardised MedDRA Query (SMQ) 'vestibular disorders'. Then we analysed cases with vestibular symptoms, based on the association of typical manifestations. The reporting rate was calculated based on the number of VD cases and the number of vaccinated patients.

RESULTS

Among 6608 cases reported to our centre related to COVID-19 vaccines during 2021, 34 VDs associated with BNT162b2 administration were included. They were mainly reported in females (79%), 62% occurred after the first dose and 32% were serious. Symptoms had completely resolved in 13 cases (38%). Vertigo was the most common symptom followed by balance disorders. Three patients received second dose without reappearance of VD. The final diagnosis was reported in 10 patients (six cases of vestibular neuritis, two cases of central VD, two cases of benign paroxysmal positional vertigo). The regional reporting rate was 26 [95% CI: 17-34] cases of VD per 1 million persons vaccinated.

CONCLUSION

Although the relationship between vaccination and VD cannot be established, clinicians should be aware of this rare adverse effect.

A unique association? A narcolepsy type 1 case comorbid with Primary Biliary Cholangitis

The aim of the study was to present a woman affected of a narcolepsy with cataplexy (narcolepsy type 1) comorbid with an asymptomatic Primary Biliary Cholangitis (PBC). The HLA haplotype was DRB1*15:01, DQA1*01:02, DQB1*06:02. The allele DQB1*06:02 has been considered until now protective for PBC and dual pathology has not been published. We think the important clinical message of the Case would be of continuing to monitor adults with narcolepsy type 1 for late complications that may be associated with other autoimmune conditions. Clinicians should be aware of the relationship between Narcolepsy and PBC. This highlights the need for screening and management in these individuals.

Autoimmune/inflammatory syndrome induced by adjuvants (ASIA): past, present, and future implications

Adjuvants, as the name indicates, are adjoined material aimed to assist in functioning as when added to vaccines they are meant to boost the effect and strongly stimulate the immune system. The response of the immune system can be unpredictable, and the autoimmune/inflammatory syndrome induced by adjuvants (ASIA) was developed to address possible adverse reactions of an autoimmune and inflammatory type that may be caused by adjuvants. While ASIA, as a syndrome, was coined and defined in 2011; reports describing patients with vague and nonspecific clinical symptoms following vaccinations appeared much earlier. In other words, ASIA came to define, arrange, and unite the variety of symptoms, related to autoimmunity, caused not by the vaccine itself, rather by the adjuvant part of the vaccine such as aluminum, among others. Accordingly, the introduction of ASIA enabled better understanding, proper diagnosis, and early treatment of the disorder. Furthermore, ASIA was shown to be associated with almost all body systems and various rheumatic and autoimmune diseases such as systemic lupus erythematosus, antiphospholipid syndrome, and systemic sclerosis. In addition, the correlation between COVID-19 and ASIA was noticed during the pandemic. In this review, we summarized the reported effects of adjuvants and medical literature before and after ASIA was defined, the several ways ASIA can manifest and impact different systems of the body, and the incidences of ASIA during the COVID-19 pandemic. It is important to clarify, that vaccines are among, if not the, most effective means of fighting infectious diseases however, we believe that vaccines manufacturing is not above criticism, particularly when it comes to added substances possessing a risk of side effects.

Narcolepsy type I-associated DNA methylation and gene expression changes in the human leukocyte antigen region

Narcolepsy type 1 (NT1) is caused by a loss of hypothalamic orexin-producing cells, and autoreactive CD4⁺ and CD8⁺ T cells have been suggested to play a role in the autoimmune mechanism. Although NT1 showed a strong association with human leukocyte antigen (HLA)-DQB1*06:02, the responsible antigens remain unidentified. We analyzed array-based DNA methylation and gene expression data for the HLA region in CD4⁺ and CD8⁺ T cells that were separated from the peripheral blood mononuclear cells of Japanese subjects (NT1, N = 42; control, N = 42). As the large number of SNPs in the HLA region might interfere with the affinity of the array probes, we conducted a comprehensive assessment of the reliability of each probe. The criteria were based on a previous study reporting that the presence of frequent SNPs, especially on the 3' side of the probe, makes the probe unreliable. We confirmed that 90.3% of the probes after general filtering in the HLA region do not include frequent SNPs, and are thus suitable for analysis, particularly in Japanese subjects. We then performed an association analysis, and found that several CpG sites in the HLA class II region of the patients were significantly hypomethylated in CD4⁺ and CD8⁺ T cells. This association was not detected when the effect of HLA-DQB1*06:02 was considered, suggesting that the hypomethylation was possibly derived from HLA-DQB1*06:02. Further RNA sequencing revealed reduced expression levels of HLA-DQB1 alleles other than HLA-DQB1*06:02 in the patients with NT1. Our results suggest the involvement of epigenetic and expressional changes in HLA-DQB1 in the pathogenesis of NT1.

Assessing vaccine safety during a pandemic: Recent experience and lessons learned for the future

During the roll out of vaccines during a pandemic, questions regarding vaccine safety often arise. This was surely true during the SARS-CoV-2 pandemic. Different tools and capabilities exist during the pre-authorization phase and post introduction each with its strengths and limitations. Here we review the various tools and their strengths and limitations and discuss what functioned well in high income settings and the limitations that unequal vaccine safety pharmacovigilance capacity imposed upon middle and low income countries.

Informing the design of a whole of life immunisation register for Australia

INTRODUCTION

In 2016, Australia launched a whole life immunisation register, the Australian Immunisation Register (AIR), building on a universal childhood register established in 1997. Immunisation Information Systems are well established in Europe, the US and elsewhere. However, a national system covering immunisation across the lifespan, with complete capture of the population and satisfactory data quality, is rare.

METHODS

A national workshop was convened in 2016 with key stakeholders from the government, new and existing vaccine users, and vaccine providers to review the ideal features of the AIR to ensure optimal effectiveness. This workshop focused on the functionality needed to identify population groups newly included in the register and support the achievement of high immunisation coverage in these groups eligible for National Immunisation Program vaccines.

RESULTS

Key recommendations included the need for bidirectional data flow between the AIR and providers; systematic approaches to the capture and recording of accurate and complete data to ascertain important denominators for subpopulations, includingAboriginal and Torres Strait Islander status, medical risk factors, occupation, ethnicity, country of birth, and vaccines given during pregnancy; linkage with other government datasets including notifiable diseases; the capture of adverse events following immunisation; ease of access by patients, providers; and by researchers.

CONCLUSIONS

Some recommendations from the workshop have informed the development and future utility of the AIR. Some recommendations from the workshop have been integrated into the current iteration of the AIR, which is more important than ever given the roll-out of COVID-19 vaccines. The accuracy and validity of data have subsequently improved through data entry controls, data integrity checks and reporting requirements. Access to AIR data for research remains protracted and costly, limitingresearch potential.

Vaccinomics: A scoping review

BACKGROUND

This scoping review summarizes a key aspect of vaccinomics by collating known associations between heterogeneity in human genetics and vaccine immunogenicity and safety.

METHODS

We searched PubMed for articles in English using terms covering vaccines routinely recommended to the general US population, their effects, and genetics/genomics. Included studies were controlled and demonstrated statistically significant associations with vaccine immunogenicity or safety. Studies of Pandemrix®, an influenza vaccine previously used in Europe, were also included, due to its widely publicized genetically mediated association with narcolepsy.

FINDINGS

Of the 2,300 articles manually screened, 214 were included for data extraction. Six included articles examined genetic influences on vaccine safety; the rest examined vaccine immunogenicity. Hepatitis B vaccine immunogenicity was reported in 92 articles and associated with 277 genetic determinants across 117 genes. Thirty-three articles identified 291 genetic determinants across 118 genes associated with measles vaccine immunogenicity, 22 articles identified 311 genetic determinants across 110 genes associated with rubella vaccine immunogenicity, and 25 articles identified 48 genetic determinants across 34 genes associated with influenza vaccine immunogenicity. Other vaccines had fewer than 10 studies each identifying genetic determinants of their immunogenicity. Genetic associations were reported with 4 adverse events following influenza vaccination (narcolepsy, GBS, GCA/PMR, high temperature) and 2 adverse events following measles vaccination (fever, febrile seizure).

CONCLUSION

This scoping review identified numerous genetic associations with vaccine immunogenicity and several genetic associations with vaccine safety. Most associations were only reported in one study. This illustrates both the potential of and need for investment in vaccinomics. Current research in this field is focused on systems and genetic-based studies designed to identify risk signatures for serious vaccine reactions or diminished vaccine immunogenicity. Such research could bolster our ability to develop safer and more effective vaccines.

Viral immunity: Basic mechanisms and therapeutic applications-a Keystone Symposia report

Viruses infect millions of people each year. Both endemic viruses circulating throughout the population as well as novel epidemic and pandemic viruses pose ongoing threats to global public health. Developing more effective tools to address viruses requires not only in-depth knowledge of the virus itself but also of our immune system's response to infection. On June 29 to July 2, 2022, researchers met for the Keystone symposium "Viral Immunity: Basic Mechanisms and Therapeutic Applications." This report presents concise summaries from several of the symposium presenters.

Immunogenicity of Different Types of Adjuvants and Nano-Adjuvants in Veterinary Vaccines: A Comprehensive Review

Vaccination is the best way to prevent and reduce the damage caused by infectious diseases in animals and humans. So, several vaccines are used for prophylactic purposes before the pathogen infects, while therapeutic vaccines strengthen the immune system after infection with the pathogen. Adjuvants are molecules, compounds, or macromolecules that enhance non-specific immunity and, in collaboration with antigen(s), can improve the body's immune responses and change the type of immune response. The potential and toxicity of adjuvants must be balanced to provide the safest stimulation with the fewest side effects. In order to overcome the limitations of adjuvants and the effective and controlled delivery of antigens, attention has been drawn to nano-carriers that can be a promising platform for better presenting and stimulating the immune system. Some studies show that nanoparticles have a more remarkable ability to act as adjuvants than microparticles. Because nano-adjuvants inactively target antigen-presenting cells (APCs) and change their chemical surface, nanoparticles also perform better in targeted antigen delivery because they cross biological barriers more easily. We collected and reviewed various types of nano-adjuvants with their specific roles in immunogenicity as a prominent strategy used in veterinary vaccines in this paper.

Vaccines and Autoimmunity-From Side Effects to ASIA Syndrome

Since vaccines are in fact manufactured chemical compounds such as drugs, the appearance of side effects following their use is not surprising. Similarly, as the main goal of vaccines is to stimulate the immune system bringing out the production of protective antibodies, autoimmune-related side effects as a consequence of increased immune activity do not seem irrational. Fortunately, the rate of such side effects is low; however, the importance of reporting adverse events following vaccinations, understanding the mechanisms behind their appearance, making early diagnosis, and appropriate treatment cannot be overemphasized. In fact, autoimmune-related side effects of vaccines, particularly those based on adjuvants, were reported long before the introduction of the autoimmune/inflammatory syndrome induced by adjuvants (ASIA). Nevertheless, ASIA gathered and united the side effects of vaccines under one title, a step which helped organize the research and call for better immune stimulators than adjuvants. New technologies and methods of making vaccines were clearly noticed during the pandemic of COVID-19 after the introduction of mRNA-based vaccines. In our current paper, we introduce the notion of side effects to vaccines, particularly those of autoimmune nature, the mechanisms of ASIA, and the main vaccines linked with the syndrome including the recent COVID-19 vaccines. The transition from side effects to ASIA is the main idea behind our work.

Nasal vaccines: solutions for respiratory infectious diseases

Nasal vaccines induce pathogen-specific dual protective immunity at mucosal surfaces and systemically throughout the body. Consequently, nasal vaccines both prevent pathogen invasion and reduce disease severity. Because of these features, nasal vaccines are considered to be a next-generation tool for preventing respiratory infectious diseases, including COVID-19. However, nasal vaccines must overcome key safety concerns given the anatomic proximity of the central nervous system (CNS) via the olfactory bulbs which lie next to the nasal cavity. This review summarizes current efforts to develop safe and effective nasal vaccines and delivery systems, as well as their clinical applications for the prevention of respiratory infections. We also discuss various concerns regarding the safety of nasal vaccines and introduce a system for evaluating them.

Sustained delivery of CpG oligodeoxynucleotide by acetalated dextran microparticles augments effector response to Computationally Optimized Broadly Reactive Antigen (COBRA) influenza hemagglutinin

A subunit or protein-based influenza vaccine can be a safer alternative to live attenuated vaccine (Flumist) and require fewer boosts than an inactivated vaccine (e.g. Fluzone). However, to form an effective subunit vaccine, an adjuvant is often needed. In this work we used electrospray to encapsulate the hydrophilic adjuvant CpG into microparticles made from the hydrophobic biodegradable polymer acetalated dextran. To understand the rate of particle degradation on CpG release, polymer that was slow (21 h at phagosomal pH 5) and fast (0.25 h at pH 5) degrading was used to encapsulate the adjuvant. The slow-degrading particles exhibited the greatest degree of innate immune stimulation of antigen-presenting cells in vitro. In mice, the broadly acting Computationally Optimized Broadly Reactive Antigen (COBRA) Y2 influenza hemagglutinin (HA) antigen was used with CpG particles, soluble CpG, or MF-59 like adjuvant Addavax. Particles and soluble CpG elicited similar induction of anti-HA antibodies and protection against lethal influenza challenge, but the sustained release particles elicited the highest levels antibody effector functions. These results demonstrate a suitable method for encapsulation of CpG oligonucleotide in a hydrophobic particle matrix, and suggest that sustained release of CpG from Ace-DEX microparticles could potentially be used to induce potent antibody effector functions.

Post-marketing surveillance study on influenza vaccine in South Korea using a nationwide spontaneous reporting database with multiple data mining methods

Safety profiles of the influenza vaccine and its subtypes are still limited. We aimed to address this knowledge gap using multiple data mining methods and calculated performance measurements to evaluate the precision of different detection methods. We conducted a post-marketing surveillance study between 2005 and 2019 using the Korea Adverse Event Reporting System database. Three data mining methods were applied: (a) proportional reporting ratio, (b) information component, and (c) tree-based scan statistics. We evaluated the performance of each method in comparison with the known adverse events (AEs) described in the labeling information. Compared to other vaccines, we identified 36 safety signals for the influenza vaccine, and 7 safety signals were unlabeled. In subtype-stratified analyses, application site disorders were reported more frequently with quadrivalent and cell-based vaccines, while a wide range of AEs were noted for trivalent and egg-based vaccines. Tree-based scan statistics showed well-balanced performance. Among the detected signals of influenza vaccines, narcolepsy requires special attention. A wider range of AEs were detected as signals for trivalent and egg-based vaccines. Although tree-based scan statistics showed balanced performance, complementary use of other techniques would be beneficial when large noise due to false positives is expected.

What respiratory physicians should know about narcolepsy and other hypersomnias

Narcolepsy and related central disorders of hypersomnolence may present to the sleep clinic with excessive daytime sleepiness. A strong clinical suspicion and awareness of the diagnostic clues, such as cataplexy, are essential to avoid unnecessary diagnostic delay. This review provides an overview of the epidemiology, pathophysiology, clinical features, diagnostic criteria and management of narcolepsy and related disorders, including idiopathic hypersomnia, Kleine-Levin syndrome (recurrent episodic hypersomnia) and secondary central disorders of hypersomnolence.

Epstein-Barr virus encephalitis with excessive daytime sleepiness as the main manifestation: Two case reports

RATIONALE

Excessive daytime sleepiness (EDS) is a clinical manifestation of various disorders. Here, we report 2 cases of EDS related to Epstein-Barr virus (EBV) encephalitis.

PATIENT CONCERNS

Both the patients were elderly men. Case 1 presented with EDS with headache and fever. Case 2 was presented with EDS only. The 2 patients slept normally at night without taking sleeping pill. They were able to get up and go to the toilet and eat by themselves during the day, but they almost slept at other times.

DIAGNOSIS

After admission, a lumbar puncture was performed to collect the cerebrospinal fluid, and next-generation sequencing showed that EBV infection was detected. Combined with the patient's head magnetic resonance imaging and clinical features, a diagnosis of EBV encephalitis was made.

INTERVENTIONS

Both patients received antiviral therapy.

OUTCOMES

Case 1 had a rapid improvement in headache and fever and was discharged from the hospital after the symptoms of EDS gradually improved. In case 2, EDS symptoms gradually improved. Two patients were followed up for 3 months after discharge, and the outcome was good.

LESSONS

EDS can also be the main clinical manifestation of viral encephalitis, and we should diagnose and identify it early and treat it promptly.

Characterization of T cell receptors reactive to HCRTNH2, pHA273-287, and NP17-31 in control and narcolepsy patients

Narcolepsy type 1 (NT1), a disorder caused by hypocretin/orexin (HCRT) cell loss, is associated with human leukocyte antigen (HLA)-DQ0602 (98%) and T cell receptor (TCR) polymorphisms. Increased CD4⁺ T cell reactivity to HCRT, especially DQ0602-presented amidated C-terminal HCRT (HCRT_NH2), has been reported, and homology with pHA_273-287 flu antigens from pandemic 2009 H1N1, an established trigger of the disease, suggests molecular mimicry. In this work, we extended DQ0602 tetramer and dextramer data to 77 cases and 44 controls, replicating our prior finding and testing 709 TCRs in Jurkat 76 T cells for functional activation. We found that fewer TCRs isolated with HCRT_NH2 (∼11%) versus pHA_273-287 or NP_17-31 antigens (∼50%) were activated by their ligand. Single-cell characterization did not reveal phenotype differences in influenza versus HCRT_NH2-reactive T cells, and analysis of TCR CDR3αβ sequences showed TCR clustering by responses to antigens but no cross-peptide class reactivity. Our results do not support the existence of molecular mimicry between HCRT and pHA_273-287 or NP_17-31.

COVID-19 and Central Nervous System Hypersomnias

Purpose of review

Central nervous system (CNS) hypersomnias can be triggered by external factors, such as infection or as a response to vaccination. The 2019 coronavirus disease (COVID-19) pandemic, which was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), led to a worldwide effort to quickly develop a vaccine to contain the pandemic and reduce morbidity and mortality. This narrative review is focused on the literature published in the past 2 years and provides an update on current knowledge in respect of the triggering of CNS hypersomnias by infection per se, vaccination, and circadian rhythm alterations caused by social isolation, lockdown, and quarantine.

Recent findings

At present, there is no consensus on the association between hypersomnias and COVID-19 vaccination or infection per se; however, the data suggest that there has been an increase in excessive daytime sleepiness due to vaccination, but only for a short duration. Kleine Levin syndrome, hypersomnia, excessive daytime sleepiness, and narcolepsy were aggravated and exacerbated in some case reports in the literature. Both increased and decreased sleep duration and improved and worsened sleep quality were described. In all age groups, delayed sleep time was frequent in studies of patients with hypersomnolence.

Summary

The hypothesis that there is a pathophysiological mechanism by which the virus, vaccination, and the effects of quarantine aggravate hypersomnias is discussed in this review.

Parental socioeconomic and psychological determinants of the 2009 pandemic influenza A(H1N1) vaccine uptake in children

BACKGROUND

Before COVID-19, the previous pandemic was caused by influenza A(H1N1)pdm09 virus in 2009. Identification of factors behind parental decisions to have their child vaccinated against pandemic influenza could be helpful in planning of other pandemic vaccination programmes. We investigated the association of parental socioeconomic and psychosocial factors with uptake of the pandemic influenza vaccine in children in 2009-2010.

METHODS

This study was conducted within a prospective birth-cohort study (STEPS Study), where children born in 2008-2010 are followed from pregnancy to adulthood. Demographic and socioeconomic factors of parents were collected through questionnaires and vaccination data from electronic registers. Before and after the birth of the child, the mother's and father's individual and relational psychosocial well-being, i.e. depressive symptoms, dissatisfaction with the relationship, experienced social and emotional loneliness, and maternal anxiety during pregnancy, were measured by validated questionnaires (BDI-II, RDAS, PRAQ, and UCLA).

RESULTS

Of 1020 children aged 6-20 months at the beginning of pandemic influenza vaccinations, 820 (80%) received and 200 (20%) did not receive the vaccine against influenza A(H1N1)pdm09. All measures of parents' psychosocial well-being were similar between vaccinated and non-vaccinated children. Children of younger mothers had a higher risk of not receiving the influenza A(H1N1)pdm09 vaccine than children of older mothers (OR 2.59, 95% CI 1.52-4.43, for mothers < 27.7 years compared to ≥ 33.6 years of age). Children of mothers with lower educational level had an increased risk of not receiving the vaccine (OR 1.46, 95% CI 1.00-2.14).

CONCLUSIONS

Mother's younger age and lower education level were associated with an increased risk for the child not to receive the 2009 pandemic influenza vaccine, but individual or relational psychosocial well-being of parents was not associated with children's vaccination. Our findings suggest that young and poorly educated mothers should receive targeted support in order to promote children's vaccinations during a pandemic.

Association of Rare Immune-Related Adverse Events to Survival in Advanced Cancer Patients Treated with Immune Checkpoint Inhibitors: A Real-World Single-Center Cohort Study

Immune checkpoint inhibitors (ICIs) are associated with immune-related (ir) adverse events (AEs) resembling autoimmune diseases. In this retrospective cohort study of patients (pts) treated with ICIs at Oulu University Hospital from 2014-2020, we analysed the spectrum of severe irAEs and their prognostic nature, focusing on rare irAEs. Pts (n = 173) with lung cancer (n = 76, 43.9%), melanoma (n = 56, 32.4%), renal and bladder cancers (n = 34, 19.7%), head and neck cancers (n = 4, 2.3%), SCC (n = 2, 1.2%), and CRC (n = 1, 0.6%) receiving single anti-PD-(L)1 (n = 160) or combination (ICI-ICI n = 9, ICI-chemotherapy n = 4) therapy were included. The survival analysis focused on single anti-PD-(L)1-treated patients with melanoma, lung cancer, and renal and bladder cancers (n = 142). Grade ≥ 3 irAEs of multiple aetiology occurred in 29 patients treated with single-PD-L1 therapy (20.4%), which was associated with improved progression-free survival (PFS) (HR 0.50, CI 0.31-0.78) but not overall survival (OS) (HR 0.88, CI 0.52-1.50). Rare grade ≥ 3 events occurred in 10 (7.0%) pts with no association with PFS (HR 0.90, CI 0.42-1.94). Hence, the presence of rare grade ≥ 3 irAEs was associated with a tendency for inferior OS (HR 1.44, CI 0.66-3.11). Pts with rare grade ≥ 3 irAEs had inferior OS, possibly reflecting the delay in diagnostic workflow and the treatment of irAEs. One explanation for the high incidence of irAEs could be the Finnish population-based genetic variation affecting the immune system.

Finnish children who experienced narcolepsy after receiving the Pandemrix vaccine during the 2009-2010 H1N1 pandemic demonstrated high level of psychosocial problems

AIM

We assessed psychosocial burdens in children who developed narcolepsy after receiving the Pandemrix H1N1 vaccine during the 2009-2010 pandemic. Parental quality of life was also assessed.

METHODS

This multicentre study covered four of the five Finnish University Hospital Districts, which dealt with about 90% of the paediatric narcolepsy cases after the Pandemrix vaccination. The medical records of children diagnosed from 2010 to 2014 were reviewed. The questionnaires included the Youth Self-Report (YSR), Children's Depression Inventory (CDI), the Child Behaviour Checklist (CBCL) and questions on parental resources, stress and quality of life.

RESULTS

We obtained the medical records of 94 children who were aged 5-17 years at the time of their narcolepsy diagnosis and questionnaire data for 73 of those children. Most children had strong narcolepsy symptoms, and 25% had CDI scores that suggested depression. In addition, 41% had total CBCL problem scores above the clinically significant limit and 48% were anxious, withdrawn and had somatic complaints. Sleep latency was weakly associated with the CBCL total problem score. Half of the children needed psychiatric interventions and parental stress was common.

CONCLUSION

Depression and behavioural problems were common in children with narcolepsy after the Pandemrix vaccination and their parents frequently reported feeling stressed.

Induction of broadly reactive influenza antibodies increases susceptibility to autoimmunity

Infection and vaccination repeatedly expose individuals to antigens that are conserved between influenza virus subtypes. Nevertheless, antibodies recognizing variable influenza epitopes greatly outnumber antibodies reactive against conserved epitopes. Elucidating factors contributing to the paucity of broadly reactive influenza antibodies remains a major obstacle for developing a universal influenza vaccine. Here, we report that inducing broadly reactive influenza antibodies increases autoreactive antibodies in humans and mice and exacerbates disease in four distinct models of autoimmune disease. Importantly, transferring broadly reactive influenza antibodies augments disease in the presence of inflammation or autoimmune susceptibility. Further, broadly reactive influenza antibodies spontaneously arise in mice with defects in B cell tolerance. Together, these data suggest that self-tolerance mechanisms limit the prevalence of broadly reactive influenza antibodies, which can exacerbate disease in the context of additional risk factors.

Postmarketing studies: can they provide a safety net for COVID-19 vaccines in the UK?

In the current era of the COVID-19 pandemic, the world has never been more interested in the process of vaccine development. While researchers across the globe race to find an effective yet safe vaccine to protect populations from the newly emergent SARS-CoV-2 virus, more than one-third of the world has been subjected to either full or partial lockdown measures. With communities having felt the burden of prolonged isolation, finding a safe and efficacious vaccine will yield direct beneficial effects on protecting against COVID-19 morbidity and mortality and help relieve the psychological and economic load on communities living with COVID-19. There is hope that with the extraordinary efforts of scientists a vaccine will become available. However, given the global public health crisis, development of a COVID-19 vaccine will need to be fast tracked through the usual prelicensing development stages and introduced with limited clinical trial data compared with those vaccines that are developed conventionally over more than a decade. In this scenario, surveillance of the vaccine in the real world becomes even more paramount. This responsibility falls to observational researchers who can provide an essential safety net by continuing to monitor the effectiveness and safety of a COVID-19 vaccine after licensing. Postauthorisation observational studies for safety and effectiveness are complementary to prelaunch clinical trials and not a replacement. In this paper, we highlight the importance of postmarketing studies for future newly licensed COVID-19 vaccines and the key epidemiological considerations.

Nano/microparticle Formulations for Universal Influenza Vaccines

Influenza affects millions of people worldwide and can result in severe sickness and even death. The best method of prevention is vaccination; however, the seasonal influenza vaccine often suffers from low efficacy and requires yearly vaccination due to changes in strain and viral mutations. More conserved universal influenza antigens like M2 ectodomain (M2e) and the stalk region of hemagglutinin (HA stalk) have been used clinically but often suffer from low antigenicity. To increase antigenicity, universal antigens have been formulated using nano/microparticles as vaccine carriers against influenza. Utilizing polymers, liposomes, metal, and protein-based particles, indicators of immunity and protection in mouse, pig, ferrets, and chicken models of influenza have been shown. In this review, seasonal and universal influenza vaccine formulations comprised of these materials including their physiochemical properties, fabrication, characterization, and biologic responses in vivo are highlighted. The review is concluded with future perspectives for nano/microparticles as carrier systems and other considerations within the universal influenza vaccine delivery landscape.

Adjuvants: Engineering Protective Immune Responses in Human and Veterinary Vaccines

Adjuvants are key components of many vaccines, used to enhance the level and breadth of the immune response to a target antigen, thereby enhancing protection from the associated disease. In recent years, advances in our understanding of the innate and adaptive immune systems have allowed for the development of a number of novel adjuvants with differing mechanisms of action. Herein, we review adjuvants currently approved for human and veterinary use, describing their use and proposed mechanisms of action. In addition, we will discuss additional promising adjuvants currently undergoing preclinical and/or clinical testing.

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

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

Influenza vaccines: Past, present, and future

Globally, infection by seasonal influenza viruses causes 3-5 million cases of severe illness and 290,000-650,000 respiratory deaths each year. Various influenza vaccines, including inactivated split- and subunit-type, recombinant and live attenuated vaccines, have been developed since the 1930s when it was discovered that influenza viruses could be cultivated in embryonated eggs. However, the protection rate offered by these vaccines is rather low, especially in very young children and the elderly. In this review, we describe the history of influenza vaccine development, the immune responses induced by the vaccines and the adjuvants applied. Further, we suggest future directions for improving the effectiveness of influenza vaccines in all age groups. This includes the development of an influenza vaccine that induces a balanced T helper cell type 1 and type 2 immune responses based on the understanding of the immune system, and the development of a broad-spectrum influenza vaccine that can increase effectiveness despite antigen shifts and drifts, which are characteristics of the influenza virus. A brighter future can be envisaged if the development of an adjuvant that is safe and effective is realized.

Safety of Influenza A H1N1pdm09 Vaccines: An Overview of Systematic Reviews

Background

In 2009, a new influenza A H1N1 virus emerged causing a global pandemic. A range of monovalent influenza A H1N1pdm09 vaccines with or without adjuvants were developed. After the mass vaccination campaigns safety concerns related to H1N1pdm09 vaccines were reported. More than a decade later, reported AEFIs are still under scrutiny. We performed a systematic review aiming to synthesize the evidence on the safety of the H1N1pdm09 vaccines on reported outcomes from existing systematic reviews.

Methods

Four electronic databases, PubMed, EMBASE, Epistimonikos and the Cochrane Database of Systematic Reviews were searched for articles on H1N1pdm09 vaccination published from 2009 to January 2021. Systematic reviews assessing short- or long-term adverse events after H1N1pdm09 vaccination were considered for inclusion. Data was extracted from all selected reviews. Outcomes were grouped and results from each included review were presented narratively and in tables.

Results

16 systematic reviews met the inclusion criteria. Reported outcomes were short-term events (3 reviews), fetal/pregnancy outcomes (8 reviews), Guillain-Barré syndrome (GBS) (4 reviews), narcolepsy (2 reviews) demyelinating diseases (1 review based on one study only) and inflammatory bowel disease (IBD) (1 review). Short-term serious adverse events were rare, 3 cases amongst 16725 subjects in 18 randomized controlled trials (0.018%). No deaths were reported. The risks of local events were generally higher for adjuvanted vaccines as compared to unadjuvanted vaccines. Maternal H1N1pdm09 vaccination in any trimester was not associated with an increase in preterm birth, small for gestational age, congenital malformations or fetal death. For GBS, results were conflicting. The main systematic review on narcolepsy found a 5-14-fold increased risk in children, and a 2-7- fold increased risk in adults after vaccination with Pandemrix. The attributable risk of narcolepsy one year after vaccination was 1 case per 18 400 vaccine doses in children/adolescents, and 1 case per 181 000 vaccine doses in adults.

Conclusion

Adjuvanted vaccines had more local but not serious adverse events compared to unadjuvanted vaccines. Vaccination with Pandemrix was strongly associated with narcolepsy, particularly in children. No increased risks of pregnancy outcomes were seen after pandemic vaccination. The findings on GBS were inconclusive.

Neurologic Safety Monitoring of COVID-19 Vaccines: Lessons From the Past to Inform the Present

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has triggered a global effort to rapidly develop and deploy effective and safe coronavirus disease 2019 (COVID-19) vaccinations. Vaccination has been one of the most effective medical interventions in human history, although potential safety risks of novel vaccines must be monitored, identified, and quantified. Adverse events must be carefully assessed to define whether they are causally associated with vaccination or coincidence. Neurologic adverse events following immunizations are overall rare but with significant morbidity and mortality when they occur. Here, we review neurologic conditions seen in the context of prior vaccinations and the current data to date on select COVID-19 vaccines including mRNA vaccines and the adenovirus-vector COVID-19 vaccines, ChAdOx1 nCOV-19 (AstraZeneca) and Ad26.COV2.S Johnson & Johnson (Janssen/J&J).

Distinct single-component adjuvants steer human DC-mediated T-cell polarization via Toll-like receptor signaling toward a potent antiviral immune response

The COVID-19 pandemic highlights the importance of efficient and safe vaccine development. Vaccine adjuvants are essential to boost and tailor the immune response to the corresponding pathogen. To allow for an educated selection, we assessed the effect of different adjuvants on human monocyte-derived dendritic cells (DCs) and their ability to polarize innate and adaptive immune responses. In contrast to commonly used adjuvants, such as aluminum hydroxide, Toll-like receptor (TLR) agonists induced robust phenotypic and functional DC maturation. In a DC-lymphocyte coculture system, we investigated the ensuing immune reactions. While monophosphoryl lipid A synthetic, a TLR4 ligand, induced checkpoint inhibitors indicative for immune exhaustion, the TLR7/8 agonist Resiquimod (R848) induced prominent type-1 interferon and interleukin 6 responses and robust CTL, B-cell, and NK-cell proliferation, which is particularly suited for antiviral immune responses. The recently licensed COVID-19 vaccines, BNT162b and mRNA-1273, are both based on single-stranded RNA. Indeed, we could confirm that the cytokine profile induced by lipid-complexed RNA was almost identical to the pattern induced by R848. Although this awaits further investigation, our results suggest that their efficacy involves the highly efficient antiviral response pattern stimulated by the RNAs' TLR7/8 activation.

Narcolepsy genetic marker HLA DQB1*06:02 and excessive daytime sleepiness in Parkinson disease patients treated with dopaminergic agents

OBJECTIVE

To determine whether narcolepsy Human Leukocyte Antigen (HLA) risk allele DQB1*0602 is associated with excessive daytime sleepiness (EDS) and inappropriate sleep in patients with Parkinson disease (PD).

BACKGROUND

EDS is a common and disabling non-motor manifestation of PD, affecting quality of life and driving performance. DQB1*0602 is an HLA risk allele for narcolepsy. It is present in 12-30% of the general population. We hypothesize that DQB1*0602 is associated with an increased risk of EDS and inappropriate sleep in PD patients.

METHODS

This was a cross-sectional observational study of 150 PD individuals on dopaminergic agents. Main outcome measures were DQB1*0602 status and the modified Epworth Sleepiness Scale. Individuals with dementia, loss of independence, narcolepsy and untreated sleep apnea were excluded. Confounding variables for EDS were assessed using Parkinson Disease Sleep Scale, Mayo Sleep Questionnaire, Unified PD Rating Scale, Hoehn and Yahr scale.

RESULTS

DQB1*06:02 positive PD patients were approximately three times more likely to experience EDS and fall asleep inappropriately during activities that required sustained alertness (e.g. driving, eating, attending work etc.). Exploratory post hoc analysis showed a dopaminergic drug dose- and type- dependent effect on daytime sleepiness in DQB1*06:02 positive individuals. No significant differences were found in confounding variables.

CONCLUSION

PD individuals are more likely to experience EDS and fall asleep inappropriately during activities if DQB1*0602 positive. Genetic vulnerability may explain EDS risk in PD.

Vaccination in acute immune-mediated/inflammatory disorders of the central nervous system

This review article covers the vaccination related issues in autoimmune disorders of central nervous system (CNS) including narcolepsy, anti-NMDAR encephalitis, Rasmussen encephalitis and febrile infection related epilepsy syndrome (FIRES). Beyond these conditions the immune mediated epilepsies related with autoimmune CNS disorders are discussed and indications and contraindications of vaccinations in these cases are also considered.

Update on Influenza Vaccines: Needs and Progress

Influenza is an annual seasonal epidemic, and occasionally pandemic, respiratory disease that causes considerable morbidity and mortality worldwide. Despite the widespread availability of safe and effective vaccines since the 1950s, this virus continues to pose a significant public health threat. Variable and often weak vaccine effectiveness, antigenic drift and shift, and vaccine hesitancy are some of the obstacles that must be overcome to control this disease. In this article, we briefly review current influenza vaccines, address safety concerns and the need for newer influenza vaccines of higher efficacy, and discuss efforts to create broadly protective, universal influenza vaccines.

3-Indoleacetonitrile Is Highly Effective in Treating Influenza A Virus Infection In Vitro and In Vivo

Influenza A viruses are serious zoonotic pathogens that continuously cause pandemics in several animal hosts, including birds, pigs, and humans. Indole derivatives containing an indole core framework have been extensively studied and developed to prevent and/or treat viral infection. This study evaluated the anti-influenza activity of several indole derivatives, including 3-indoleacetonitrile, indole-3-carboxaldehyde, 3-carboxyindole, and gramine, in A549 and MDCK cells. Among these compounds, 3-indoleacetonitrile exerts profound antiviral activity against a broad spectrum of influenza A viruses, as tested in A549 cells. Importantly, in a mouse model, 3-indoleacetonitrile with a non-toxic concentration of 20 mg/kg effectively reduced the mortality and weight loss, diminished lung virus titers, and alleviated lung lesions of mice lethally challenged with A/duck/Hubei/WH18/2015 H5N6 and A/Puerto Rico/8/1934 H1N1 influenza A viruses. The antiviral properties enable the potential use of 3-indoleacetonitrile for the treatment of IAV infection.

A role for pathogen risk factors and autoimmunity in encephalitis lethargica?

The encephalitis lethargica (EL) epidemic swept the world from 1916 to 1926 and is estimated to have afflicted between 80,000 to one million people. EL is an unusual neurological illness that causes profound sleep disorders, devastating neurological sequalae and, in many cases, death. Though uncommon, EL is still occasionally diagnosed today when a patient presents with an acute or subacute encephalitic illness, where all other known causes of encephalitis have been excluded and criteria for EL are met. However, it is impossible to know whether recent cases of EL-like syndromes result from the same disease that caused the epidemic. After more than 100 years of research into potential pathogen triggers and the role of autoimmune processes, the aetiology of EL remains unknown. The epidemic approximately coincided with the 1918 H1N1 influenza pandemic but the evidence of a causal link is inconclusive. This article reviews the literature on the causes of EL with a focus on autoimmune mechanisms. In light of the current pandemic, we also consider the parallels between the EL epidemic and neurological manifestations of COVID-19. Understanding how pathogens and autoimmune processes can affect the brain may well help us understand the conundrum of EL and, more importantly, will guide the treatment of patients with suspected COVID-19-related neurological disease, as well as prepare us for any future epidemic of a neurological illness.

Review: Vaccine Myth-Buster - Cleaning Up With Prejudices and Dangerous Misinformation

Although vaccines have already saved and will continue to save millions of lives, they are under attack. Vaccine safety is the main target of criticism. The rapid distribution of false information, or even conspiracy theories on the internet has tremendously favored vaccine hesitancy. The World Health Organization (WHO) named vaccine hesitancy one of the top ten threats to global health in 2019. Parents and patients have several concerns about vaccine safety, of which the ubiquitous anxieties include inactivating agents, adjuvants, preservatives, or new technologies such as genetic vaccines. In general, increasing doubts concerning side effects have been observed, which may lead to an increasing mistrust of scientific results and thus, the scientific method. Hence, this review targets five topics concerning vaccines and reviews current scientific publications in order to summarize the available information refuting conspiracy theories and myths about vaccination. The topics have been selected based on the author's personal perception of the most frequently occurring safety controversies: the inactivation agent formaldehyde, the adjuvant aluminum, the preservative mercury, the mistakenly-drawn correlation between vaccines and autism and genetic vaccines. The scientific literature shows that vaccine safety is constantly studied. Furthermore, the literature does not support the allegations that vaccines may cause a serious threat to general human life. The author suggests that more researchers explaining their research ideas, methods and results publicly could strengthen the general confidence in science. In general, vaccines present one of the safest and most cost-effective medications and none of the targeted topics raised serious health concerns.

Targeting Antigens for Universal Influenza Vaccine Development

Traditional influenza vaccines generate strain-specific antibodies which cannot provide protection against divergent influenza virus strains. Further, due to frequent antigenic shifts and drift of influenza viruses, annual reformulation and revaccination are required in order to match circulating strains. Thus, the development of a universal influenza vaccine (UIV) is critical for long-term protection against all seasonal influenza virus strains, as well as to provide protection against a potential pandemic virus. One of the most important strategies in the development of UIVs is the selection of optimal targeting antigens to generate broadly cross-reactive neutralizing antibodies or cross-reactive T cell responses against divergent influenza virus strains. However, each type of target antigen for UIVs has advantages and limitations for the generation of sufficient immune responses against divergent influenza viruses. Herein, we review current strategies and perspectives regarding the use of antigens, including hemagglutinin, neuraminidase, matrix proteins, and internal proteins, for universal influenza vaccine development.

Single center analysis of patients with H1N1 vaccine-related narcolepsy and sporadic narcolepsy presenting over the same time period

STUDY OBJECTIVES

We aimed to describe the clinical features of narcolepsy in patients referred to our sleep center between 2009 and 2016, and to compare these features across age groups and between sporadic vs AS03-adjuvanted H1N1 influenza vaccine-related patients.

METHODS

This is a retrospective, consecutive study of adult and pediatric narcolepsy patients in the Republic of Ireland. All participants underwent structured assessments, including polysomnography and the Multiple Sleep Latency Test. Brain magnetic resonance imaging, hypocretin levels, and human leukocyte antigen typing were also carried out on the majority of patients. Patients were compared across age groups as well as etiology.

RESULTS

The conditions of 40 (74%) patients were vaccine-related. The median age was 13.5 years and time from symptom onset to diagnosis was 112 weeks. Median time from vaccination to symptom onset was 26 weeks. In children, hypnogogic hallucinations and sleep paralysis were less frequent than in adults (17% vs 67%, P = .018 and 0% vs 75%, P < .0005). Sleep latency determined by the Multiple Sleep Latency Test was shorter in children than adults (median 1.75 vs 4 minutes, P = .011). Patients with vaccine-related and sporadic narcolepsies had typical clinical presentations. Vaccine-related patients had longer polysomnography latency (median 10.5 vs 5 minutes, P = .043), longer stage N2 sleep (209.6 ± 44.6 vs 182.3 ± 34.2 minutes, P = .042), and a trend toward longer total sleep times (P = .09). No differences were noted in relation to Multiple Sleep Latency Test, hypocretin, human leukocyte antigen typing, and magnetic resonance imaging.

CONCLUSIONS

Results show that vaccine-related patients greatly outnumbered sporadic patients during the study period and suggest that sporadic and vaccine-related narcolepsy are clinically similar entities.