Effect of vaccinations on seizure risk and disease course in Dravet syndrome

COVID-19 infection and vaccination in children with Dravet syndrome or infantile epileptic spasms syndrome: An internet survey in Japan

BACKGROUND

This study aimed to clarify the status of coronavirus disease 2019 (COVID-19) infection and vaccination among children with infantile-onset drug-resistant epilepsy through an internet survey involving Dravet syndrome (DS) and infantile epileptic spasms syndrome (IESS) family associations.

METHODS

A web-based survey was conducted between October and November 2023, targeting parents of children aged ≤15 years with DS or IESS who were members of the Dravet Syndrome JP or West Syndrome JP family associations, covering patient characteristics, COVID-19 infection, and vaccination.

RESULTS

A total of 151 and 112 responses were obtained. COVID-19 infections occurred in 68.2 % and 52.7 % of DS and IESS cases, respectively. Fever-triggered seizures were reported in 61.8 % of DS and 3.6 % of IESS cases. Among DS cases, 22.8 % (8.0 % vaccinated), 36.6 % (20.0 % vaccinated), and 34.0 % (16.0 % vaccinated) required temporary visits for seizure exacerbation, emergency visits for seizure clusters/status epilepticus, and seizure-related hospitalizations, respectively. Vaccination rates were 25.3 % for DS and 17.3 % for IESS. Post-vaccination fever-triggered seizures occurred in 2.9 % and 3.5 % of DS cases after the first and second doses, respectively, and 0.0 % of IESS cases. Among DS cases, temporary visits were required in 2.9 % and 0.0 %, emergency visits in 0.0 % for both doses and hospitalizations in 2.9 % and 3.5 %, respectively. Vaccine hesitancy arising from seizure concerns was reported by 66.4 % and 23.0 % of DS and IESS caregivers, respectively.

CONCLUSION

COVID-19 vaccination is well-tolerated and may lower seizure risks in children with DS. However, caregivers should monitor those with a history of fever-triggered seizures.

Virus-Induced Epilepsy vs. Epilepsy Patients Acquiring Viral Infection: Unravelling the Complex Relationship for Precision Treatment

The intricate relationship between viruses and epilepsy involves a bidirectional interaction. Certain viruses can induce epilepsy by infecting the brain, leading to inflammation, damage, or abnormal electrical activity. Conversely, epilepsy patients may be more susceptible to viral infections due to factors, such as compromised immune systems, anticonvulsant drugs, or surgical interventions. Neuroinflammation, a common factor in both scenarios, exhibits onset, duration, intensity, and consequence variations. It can modulate epileptogenesis, increase seizure susceptibility, and impact anticonvulsant drug pharmacokinetics, immune system function, and brain physiology. Viral infections significantly impact the clinical management of epilepsy patients, necessitating a multidisciplinary approach encompassing diagnosis, prevention, and treatment of both conditions. We delved into the dual dynamics of viruses inducing epilepsy and epilepsy patients acquiring viruses, examining the unique features of each case. For virus-induced epilepsy, we specify virus types, elucidate mechanisms of epilepsy induction, emphasize neuroinflammation's impact, and analyze its effects on anticonvulsant drug pharmacokinetics. Conversely, in epilepsy patients acquiring viruses, we detail the acquired virus, its interaction with existing epilepsy, neuroinflammation effects, and changes in anticonvulsant drug pharmacokinetics. Understanding this interplay advances precision therapies for epilepsy during viral infections, providing mechanistic insights, identifying biomarkers and therapeutic targets, and supporting optimized dosing regimens. However, further studies are crucial to validate tools, discover new biomarkers and therapeutic targets, and evaluate targeted therapy safety and efficacy in diverse epilepsy and viral infection scenarios.

Do vaccines cause epilepsy? Review of cases in the National Vaccine Injury Compensation Program

OBJECTIVE

The National Childhood Vaccine Injury Act of 1986 created the National Vaccine Injury Compensation Program (VICP), a no-fault alternative to the traditional tort system. Since 1988, the total compensation paid exceeds $5 billion. Although epilepsy is one of the leading reasons for filing a claim, there has been no review of the process and validity of the legal outcomes given current medical information. The objectives were to review the evolution of the VICP program in regard to vaccine-related epilepsy and assess the rationale behind decisions made by the court.

METHODS

Publicly available cases involving epilepsy claims in the VICP were searched through Westlaw and the US Court of Federal Claims websites. All published reports were reviewed for petitioner's theories supporting vaccine-induced epilepsy, respondent's counterarguments, the final decision regarding compensation, and the rationale underlying these decisions. The primary goal was to determine which factors went into decisions regarding whether vaccines caused epilepsy.

RESULTS

Since the first epilepsy case in 1989, there have been many changes in the program, including the removal of residual seizure disorder as a vaccine-related injury, publication of the Althen prongs, release of the acellular form of pertussis, and recognition that in genetic conditions the underlying genetic abnormality rather than the immunization causes epilepsy. We identified 532 unique cases with epilepsy: 105 with infantile spasms and 427 with epilepsy without infantile spasms. The petitioners' experts often espoused outdated, erroneous causation theories that lacked an acceptable medical or scientific foundation and were frequently criticized by the court.

SIGNIFICANCE

Despite the lack of epidemiological or mechanistic evidence indicating that childhood vaccines covered by the VICP result in or aggravate epilepsy, these cases continue to be adjudicated. After 35 years of intense litigation, it is time to reconsider whether epilepsy should continue to be a compensable vaccine-induced injury.

Effects of coronavirus disease 2019 vaccination on seizures in patients with epilepsy

BACKGROUND

Given that seizures may be triggered by vaccination, this study aimed to evaluate the risk and correlative factors of seizures in patients with epilepsy (PWE) after being vaccinated against coronavirus disease 2019 (COVID-19).

METHODS

This study retrospectively enrolled PWE who were vaccinated against COVID-19 in the epilepsy centers of 11 hospitals in China. We divided the PWE into two groups as follows: (1) patients who developed seizures within 14 days of vaccination were assigned to the SAV (with seizures after vaccination) group; (2) patients who were seizure-free within 14 days of vaccination were assigned to the SFAV (seizure-free after vaccination) group. To identify potential risk factors for seizure reccurence, the binary logistic regression analysis was performed. Besides, 67 PWE who had not been vaccinated were also included for elucidating the effects of vaccination on seizures recurrence, and binary logistic regression analysis was performed to determine whether vaccination would affect the recurrence rate of PWE who had drug reduction or withdrawal.

RESULTS

The study included a total of 407 patients; of which, 48 (11.8%) developed seizures within 14 days after vaccination (SAV group), whereas 359 (88.2%) remained seizure-free (SFAV group). The binary logistic regression analysis revealed that duration of seizure freedom ( P  < 0.001) and withdrawal from anti-seizure medications (ASMs) or reduction in their dosage during the peri-vaccination period were significantly associated with the recurrence of seizures (odds ratio = 7.384, 95% confidence interval = 1.732-31.488, P  = 0.007). In addition, 32 of 33 patients (97.0%) who were seizure-free for more than three months before vaccination and had a normal electroencephalogram before vaccination did not have any seizures within 14 days of vaccination. A total of 92 (22.6%) patients experienced non-epileptic adverse reactions after vaccination. Binary logistic regression analysis results showed that vaccine did not significantly affect the recurrence rate of PWE who had the behavior of ASMs dose reduction or withdrawal ( P  = 0.143).

CONCLUSIONS

PWE need protection from the COVID-19 vaccine. PWE who are seizure-free for >3 months before vaccination should be vaccinated. Whether the remaining PWE should be vaccinated depends on the local prevalence of COVID-19. Finally, PWE should avoid discontinuing ASMs or reducing their dosage during the peri-vaccination period.

Complications of Influenza A or B Virus Infection in Individuals With SCN1A-Positive Dravet Syndrome

BACKGROUND AND OBJECTIVES

To determine the frequency and spectrum of complications of influenza infection in individuals with SCN1A-positive Dravet syndrome (SCN1A-DS).

METHODS

Individuals with SCN1A-DS were identified in neurologists' care at 2 hospitals in Melbourne, Australia, with additional searches of EEG databases, the Victorian PAEDS FluCan influenza database, and the University of Melbourne Epilepsy Genetics Research Program database. Medical records were searched and families questioned to identify individuals who had an influenza infection; reported infections were confirmed by pathology report. For these individuals, we obtained baseline clinical characteristics and clinical details of the influenza infection.

RESULTS

Twenty-one of 82 individuals (26%) had 24 documented influenza infections (17 influenza A and 7 influenza B) at age 0.5-25 years (median 4 years). All presented to hospital, 18/24 (75%) for status epilepticus or seizure exacerbations. Recovery was prompt in 18/24 (75%) infections, delayed but complete in 1/24 (4%) and incomplete in 5/24 (21%). One child died from influenza pneumonia, and long-term neurologic sequelae were seen with 4 infections. These individuals were poorly responsive after termination of status epilepticus. Brain imaging in 2 showed cerebral edema and 1 also having imaging features of laminar necrosis. All have ongoing neurologic deficits compared with their baseline, 1 having profound global impairment.

DISCUSSION

Our data show that patients with SCN1A-DS are highly susceptible to neurologic complications during and severe sequelae after influenza infection, including moderate to severe persistent neurologic impairments and death. Safe administration of the seasonal influenza vaccine should be prioritized for this population.

Combined measles-mumps-rubella-varicella vaccine and febrile convulsions: the risk considered in the broad context

INTRODUCTION

Studies on quadrivalent measles, mumps, rubella, and varicella (MMRV) vaccines have indicated a twofold increased relative risk of febrile convulsion (FC) after the first dose compared to MMR and V administered at the same medical visit (MMR+V).

AREAS COVERED

This narrative review contextualizes FC occurrence after the first MMRV vaccine dose from a clinical perspective and outlines approaches to attenuate FC occurrence post-vaccination.

EXPERT OPINION

While the relative FC risk increases after the first dose of MMRV compared to MMR+V vaccine in measles-naïve infants, the attributable risk is low versus the overall FC risk in the pediatric population triggered by other causes, like natural exposure to pathogens or routine vaccination. No increased risk of FC has been reported after MMRV co-administration with other routine vaccines compared to MMRV alone. Based on our findings and considering the MMRV vaccination benefits (fewer injections, higher coverage, better vaccination compliance), the overall benefit-risk profile of MMRV vaccine is considered to remain positive. Potential occurrence of FC in predisposed children (e.g. with personal/family history of FC) may be attenuated if they receive MMR+V instead of MMRV as the first dose. It is also important to monitor vaccinees for fever during the first 2 weeks post-vaccination.

COVID-19 vaccination for patients with benign childhood epilepsy with centrotemporal spikes

AIM

There is a high demand for information on COVID-19 vaccination for patients with childhood epilepsy with centrotemporal spikes (BECTS). Patients with this condition need a stable, daily life; unfortunately, the decision of vaccination is not easy for their parents. We evaluated patients with BECTS for symptoms and seizure control after COVID-19 vaccination.

METHODS

We asked the caregivers of all patients who visited our hospital to report their vaccination status, and if vaccinated, their experience in terms of adverse effects and seizure control after the second dose of the four Chinese-approved COVID-19 vaccines.

RESULTS

Seventy-seven children had received their second COVID-19 vaccine dose: 58 of 77 (75.3%) received Sinopharm (Beijing): BBIBP-CorV (Vero cells) and 16 (20.8%) received CanSino: Ad5-nCoV. Twenty of seventy-seven (25.97%) patients with BECTS reported having side effects; all effects were mild that could be relieved themselves. For Sinopharm (Beijing): BBIBP-CorV (Vero cells), the most frequent local side effect reported by the parents was pain at the site of injection (17.24%) and systematic side effect was fatigue (15.52%). For CanSino: Ad5-nCoV, the most reported local side effect was pain at the site of injection (6.25%). All parents reported that their child's side effects could be relieved by themselves. No patient reported status epilepticus or exacerbation of a pre-existing condition. If non-vaccinated, the cause of hesitation was explored: 40% of parents worried about inducing seizures, 19% of parents worried about vaccine side effects, 32% of parents worried about the vaccine-antiepileptic drug interactions, and 9% of parents feared for their child's physical condition. More than 34.1% of parents accepted that the decision to get the vaccine for their child was difficult. Over 90% of parents believe that research on the safety and tolerability of vaccination would help them to make the decision.

CONCLUSION

Our data suggest that COVID-19 vaccination is well tolerated and safe in patients below 18 years of age having BECTS, thereby supporting the recommendation of vaccination.

Crisis of confidence in vaccination and the role of social media

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Vaccination and childhood epilepsies

INTRODUCTION

The evidence relating vaccination to febrile seizures and epilepsy is evaluated with an emphasis on febrile seizures (FS), Dravet syndrome (DS), West syndrome, and other developmental and epileptic encephalopathies.

METHODS

A systematic literature review using search words vaccination/immunization AND febrile seizures/epilepsy/Dravet/epileptic encephalopathy/developmental encephalopathy was performed. The role of vaccination as the cause/trigger/aggravation factor for FS or epilepsies and preventive measures were analyzed.

RESULTS

From 1428 results, 846 duplicates and 447 irrelevant articles were eliminated; 120 were analyzed.

CONCLUSIONS

There is no evidence that vaccinations cause epilepsy in healthy populations. Vaccinations do not cause epileptic encephalopathies but may be non-specific triggers to seizures in underlying structural or genetic etiologies. The first seizure in DS may be earlier in vaccinated versus non-vaccinated patients, but developmental outcome is similar in both groups. Children with a personal or family history of FS or epilepsy should receive all routine vaccinations. This recommendation includes DS. The known risks of the infectious diseases prevented by immunization are well established. Vaccination should be deferred in case of acute illness. Acellular pertussis DTaP (diphtheria-tetanus-pertussis) is recommended. The combination of certain vaccine types may increase the risk of febrile seizures however the public health benefit of separating immunizations has not been proven. Measles-containing vaccine should be administered at age 12-15 months. Routine prophylactic antipyretics are not indicated, as there is no evidence of decreased FS risk and they can attenuate the antibody response following vaccination. Prophylactic measures (preventive antipyretic medication) are recommended in DS due to the increased risk of prolonged seizures with fever.

Vaccination deferral among children with seizures in Zhejiang: influence, recommendation, safety and implications

OBJECTIVES

Delayed vaccination in children with seizures was common in China. This study aims to describe the vaccination status, reasons for vaccination deferral, vaccination recommendations and the safety for these patients in Zhejiang.

METHODS

1539 children included were divided into febrile seizure (FS) group, epilepsy (EP) group, unclassified seizure group and other symptomatic seizure group. Medical records and reasons for the vaccination deferral were collected by questionnaire. Vaccination data and Adverse Event Following Immunization were retrieved from vaccination booklets.

RESULTS

The main diseases of children enrolled were FS (756, 49.1%) and EP (443, 28.8%). Most of them (95.6%) were vaccinated on time before the onset of seizure, but their vaccination was delayed after seizure occurred. 76.1% were recommended to receive vaccines normally, of which the FS group accounted for the highest proportion (90.3%). 88.73% of them were vaccinated as recommended, and no serious side effects or seizure occurred. The main reason for vaccination deferral was providers' and parents' hesitation to have them vaccinated.

CONCLUSION

Seizures were overestimated as a contraindication for vaccination in China. Routine vaccination was safe in most circumstances. It is essential to educate providers and parents about the benefits and contraindications of vaccination in children with seizures.

The impact of SARS-CoV-2 vaccination in Dravet syndrome: A UK survey

BACKGROUND

The COVID-19 pandemic led to the urgent need for accelerated vaccine development. Approved vaccines have proved to be safe and well tolerated across millions of people in the general population. Dravet syndrome (DS) is a severe, early onset, developmental and epileptic encephalopathy. Vaccination is a precipitating factor for seizures. While there is no evidence that vaccine-precipitated seizures lead to adverse outcomes in people with DS, fear surrounding vaccination can remain for caregivers of people with DS, in some cases resulting in rejection of recommended vaccinations, leaving individuals more vulnerable to the relevant infections. A greater understanding of the safety profile of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in this vulnerable group will help provide guidance for caregivers and clinicians when considering vaccination.

METHODS

A cross-sectional survey regarding COVID-19 and SARS-CoV-2 vaccine, in people with DS, was conducted by Dravet Syndrome UK (DSUK). Concomitantly, a review of individuals with DS who had recently received the SARS-CoV-2 vaccine, and who are resident at the Chalfont Centre for Epilepsy (CCE), or attend epilepsy clinics at the National Hospital for Neurology and Neurosurgery (NHNN), was undertaken.

RESULTS

Thirty-eight people completed the DSUK survey. Thirty-seven percent of caregivers reported being concerned about someone with DS receiving the SARS-CoV-2 vaccine; with some reporting that they would decline a vaccine when offered. Seventy-seven percent had not received any advice from a healthcare professional about the SARS-CoV-2 vaccination. 18/38 were eligible for SARS-CoV-2 vaccination, of whom nine had received their first vaccine dose. Combining the results of the DSUK survey and the review of individuals monitored at CCE or NHNN, fifteen people with DS had received their first dose of the SARS-CoV-2 vaccine. 11/15 (73%) reported at least one side effect, the most common being fatigue (6/15; 40%) and fever (6/15; 40%). Three individuals (20%) reported an increase in seizure frequency after the first vaccine dose. No increase in seizure frequency or duration was reported after the second dose.

CONCLUSION

Overall, these results suggest that SARS-CoV-2 vaccines are safe and well tolerated in individuals with DS, as they are in most people without DS. In most people with DS, SARS-CoV-2 vaccine does not appear to be associated with an increase in the frequency or duration of seizures, even in those who develop fever post-vaccination. Many caregivers are concerned about a person with DS receiving a SARS-CoV-2 vaccine, with some reporting that they would decline a SARS-CoV-2 vaccine when offered. It is crucial that healthcare professionals are proactive in providing accurate information regarding the risks and benefits of vaccination in this population, given the potential for serious outcomes from infection.

Is SARS-CoV-2 vaccination safe and effective for elderly individuals with neurodegenerative diseases?

Introduction

Coronavirus Disease 2019 (COVID-19) poses a substantial threat to the lives of the elderly, especially those with neurodegenerative diseases, and vaccination against viral infections is recognized as an effective measure to reduce mortality. However, elderly patients with neurodegenerative diseases often suffer from abnormal immune function and take multiple medications, which may complicate the role of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines. Currently, there is no expert consensus on whether SARS-CoV-2 vaccines are suitable for patients with neurodegenerative diseases.

Areas covered

We searched Pubmed to conduct a systematic review of published studies, case reports, reviews, meta-analyses, and expert guidelines on the impact of SARS-CoV-2 on neurodegenerative diseases and the latest developments in COVID-19 vaccines. We also summarized the interaction between vaccines and age-related neurodegenerative diseases. The compatibility of future SARS-CoV-2 vaccines with neurodegenerative diseases is discussed.

Expert opinion

Vaccines enable the body to produce immunity by activating the body’s immune response. The pathogenesis and treatment of neurodegenerative diseases is complex, and these diseases often involve abnormal immune function, which can substantially affect the safety and effectiveness of vaccines. In short, this article provides recommendations for the use of vaccine candidates in patients with neurodegenerative diseases.

The impact of COVID-19 in Dravet syndrome: A UK survey

Objectives

To understand the risks, impact and outcome of COVID‐19 in people affected by Dravet Syndrome (DS).

Materials and Methods

An anonymous cross‐sectional online survey was conducted between June 17 and July 13, 2020, addressed to families of people with DS.

Results

A total of 116 responses were collected, from families of children (n = 86; 74%) and adults (30; 26%) with DS. The majority (106; 91%) were shielded at the family home during lockdown. Symptoms compatible with COVID‐19 were reported in 22 (19%) individuals. Only four individuals with symptoms had a PCR swab test, none of which was positive. Only one symptomatic person had antibody testing (but not swab testing), which was positive. One person had repeatedly positive swab tests whilst in hospital for renal failure, but had no typical symptoms of COVID‐19. In 50% of people with DS who developed possible or probable COVID‐19 symptoms, seizure worsening was reported, in terms of increased seizure frequency or duration or both. Medical attention was required in 9/22 (41%), all of whom were children.

Conclusions

In this cohort of people with DS, we observed an infection rate, determined by compatible symptoms, of 19%, with no deaths and benign outcome in most cases despite the underlying complex epilepsy although children often required medical attention. Early adoption of preventative measures, including testing of symptomatic individuals, regular surveillance for people living in residential care facilities, and shielding of individuals with comorbidities increasing the risk of severe outcome, may limit the impact of COVID‐19.

Revaccination outcomes of children with vaccine proximate seizures

BACKGROUND

Seizures, whether febrile or afebrile, occurring within 14 days following vaccination can be considered as vaccine proximate seizures (VPSs). While the attributable risk and clinical severity of first febrile VPS is well known, the risk and clinical outcomes of VPS recurrence is less well defined.

METHODS

We conducted a retrospective review of revaccination management and outcomes in children who experienced a VPS as their first seizure seen in Australian Specialist Immunisation Clinics between 2013 and 2017. Vaccination outcomes were compared between children who had a VPS as their only seizure (VPS only) and children who had further non-vaccine proximate seizures following their initial VPS (VPS+) prior to review at the clinic.

RESULTS

We identified 119 children with a VPS as their first seizure, of which 61 (51%) went on to have other seizures (VPS+). Children with VPS+ were more likely to present at a younger age (6.2 vs 12.5 months, P = 0.03), with afebrile seizures (42.6% vs 15.5%, P = 0.002) compared to VPS only children. VPS recurrence on revaccination was uncommon in both groups, but more common in VPS+ children (12.5% vs 2.4%, P = 0.07). Having an epilepsy diagnosis, specifically Dravet syndrome, was associated with VPS recurrence (P < 0.001). Of the four children with Dravet syndrome who had VPS recurrence, all had status epilepticus following revaccination.

CONCLUSION

In children who presented with a single VPS as their only seizure, VPS recurrence on revaccination was uncommon. Children who had multiple non-vaccine proximate seizures following their initial VPS (VPS+) were more likely to present with afebrile VPS, at a younger age and have a VPS recurrence with vaccination. In these children, particularly those aged < 12 months, assessment and investigation for diagnosis of Dravet syndrome should be considered and additional precautions for revaccination undertaken as they are at highest risk of VPS recurrence.

[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.

Adverse Events Following Immunization Among Children With Epilepsy: A Self-Controlled Case Series

BACKGROUND

In children with epilepsy, fever and illness are known triggers for seizure; therefore, clinicians and parents could be concerned that immunization-induced inflammation and fever could also trigger seizures. We sought to estimate the risk of emergency department (ED) visit or hospitalization for epilepsy/seizure and all causes after immunization in children younger than 7 years of age with epilepsy.

METHODS

We conducted a self-controlled case series of children diagnosed with epilepsy before their 7th birthday and immunized from 2005 to 2015 in Ontario (population 14.2 million) and Manitoba (population 1.3 million), Canada, using administrative healthcare data. We estimated the age- and season-adjusted relative incidence (aRI) of epilepsy/seizure-related and all-cause ED visits/hospitalizations during various risk periods 0-28 days after inactivated and live immunizations versus a control period 35-83 days postimmunization. Estimates from each province were analyzed separately and then combined in a random-effects meta-analysis.

RESULTS

The combined risk of epilepsy/seizure-related hospitalization/ED visit was increased 0-2 days after inactivated vaccines (aRI = 1.5, 95% confidence interval: 1.1-1.9) and 7-10 days after live vaccines (aRI = 1.9, 1.4-2.7). For all-cause ED visit/hospitalization, the combined aRI estimate was 0.9 (0.8-1.2) 0-2 days after inactivated vaccines and 1.3 (1.1-1.5) 7-10 days after live vaccines.

CONCLUSIONS

The risk of epilepsy/seizure-related ED visit/hospitalization was modestly increased among children with epilepsy during peak periods of fever and inflammation following inactivated and live vaccines. These risks must be balanced against the risk of complications from vaccine-preventable diseases.

Causality assessment of adverse events following immunization: the problem of multifactorial pathology

The analysis of Adverse Events Following Immunization (AEFI) is important in a balanced epidemiological evaluation of vaccines and in the issues related to national vaccine injury compensation programs. If manufacturing defects or vaccine storage and delivering errors are excluded, the majority of adverse reactions to vaccines occur as excessive or biased inflammatory and immune responses. These unwanted phenomena, occasionally severe, are associated with many different endogenous and exogenous factors, which often interact in complex ways. The confirmation or denial of the causal link between an AEFI and vaccination is determined pursuant to WHO guidelines, which propose a four-step analysis and algorithmic diagramming. The evaluation process from the onset considers all possible "other causes" that can explain the AEFI and thus exclude the role of the vaccine. Subsequently, even if there was biological plausibility and temporal compatibility for a causal association between the vaccine and the AEFI, the guidelines ask to look for any possible evidence that the vaccine could not have caused that event. Such an algorithmic method presents some concerns that are discussed here, in the light of the multifactorial nature of the inflammatory and immune pathologies induced by vaccines, including emerging knowledge of genetic susceptibility to adverse effects. It is proposed that the causality assessment could exclude a consistent association of the adverse event with the vaccine only when the presumed "other cause" is independent of an interaction with the vaccine. Furthermore, the scientific literature should be viewed not as an exclusion criterion but as a comprehensive analysis of all the evidence for or against the role of the vaccine in causing an adverse reaction. These issues are discussed in relation to the laws that, in some countries, regulate the mandatory vaccinations and the compensation for those who have suffered serious adverse effects.

Causality assessment of adverse events following immunization: the problem of multifactorial pathology

The analysis of Adverse Events Following Immunization (AEFI) is important in a balanced epidemiological evaluation of vaccines and in the issues related to vaccine injury compensation programs. The majority of adverse reactions to vaccines occur as excessive or biased inflammatory and immune responses. These unwanted phenomena, occasionally severe, are associated with many different endogenous and exogenous factors, which often interact in complex ways. The confirmation or denial of the causal link between an AEFI and vaccination is determined pursuant to WHO guidelines, which propose a four-step analysis and algorithmic diagramming. The evaluation process from the onset considers all possible "other causes" that might explain the AEFI and thus exclude the role of the vaccine. Subsequently, even if there was biological plausibility and temporal compatibility for a causal association between the vaccine and the AEFI, the guidelines ask to look for any possible evidence that the vaccine could not have caused that event. Such an algorithmic method presents several concerns that are discussed here, in the light of the multifactorial nature of the inflammatory and immune pathologies induced by vaccines, including emerging knowledge of genetic susceptibility to adverse effects. It is proposed that the causality assessment could exclude a consistent association of the adverse event with the vaccine only when the presumed "other cause" is independent of an interaction with the vaccine. Furthermore, the scientific literature should be viewed not as an exclusion criterion but as a comprehensive analysis of all the evidence for or against the role of the vaccine in causing an adverse reaction. Given these inadequacies in the evaluation of multifactorial diseases, the WHO guidelines need to be reevaluated and revised. These issues are discussed in relation to the laws that, in some countries, regulate the mandatory vaccinations and the compensation for those who have suffered serious adverse effects.

SCN1A Variants in vaccine-related febrile seizures: A prospective study

OBJECTIVE

Febrile seizures may follow vaccination. Common variants in the sodium channel gene, SCN1A, are associated with febrile seizures, and rare pathogenic variants in SCN1A cause the severe developmental and epileptic encephalopathy Dravet syndrome. Following vaccination, febrile seizures may raise the specter of poor outcome and inappropriately implicate vaccination as the cause. We aimed to determine the prevalence of SCN1A variants in children having their first febrile seizure either proximal to vaccination or unrelated to vaccination compared to controls.

METHODS

We performed SCN1A sequencing, blind to clinical category, in a prospective cohort of children presenting with their first febrile seizure as vaccine proximate (n = 69) or as non-vaccine proximate (n = 75), and children with no history of seizures (n = 90) recruited in Australian pediatric hospitals.

RESULTS

We detected 2 pathogenic variants in vaccine-proximate cases (p.R568X and p.W932R), both of whom developed Dravet syndrome, and 1 in a non-vaccine-proximate case (p.V947L) who had febrile seizures plus from 9 months. All had generalized tonic-clonic seizures lasting >15 minutes. We also found enrichment of a reported risk allele, rs6432860-T, in children with febrile seizures compared to controls (odds ratio = 1.91, 95% confidence interval = 1.31-2.81).

INTERPRETATION

Pathogenic SCN1A variants may be identified in infants with vaccine-proximate febrile seizures. As early diagnosis of Dravet syndrome is essential for optimal management and outcome, SCN1A sequencing in infants with prolonged febrile seizures, proximate to vaccination, should become routine. ANN NEUROL 2020;87:281-288.

Incomplete Vaccination Among Children With Special Health Care Needs in Zhejiang, China: Analysis of Retrospective Data

Objective: There is a lack of data relating to vaccination of children with special health care needs (CSHCN) and its influencing factors in China. We investigated the disease spectrum of CSHCN at the Vaccination Consultation Clinic in Zhejiang province as well as the underlying factors of vaccination recommendations of these children. Methods: In this study, we retrospectively analyzed the data of 4,525 CSHCN, who visited to our clinic for a vaccination consultation from January 1, 2016 to May 30, 2018. Descriptive data were presented as mean ± standard deviation (SD) and percentages. Multivariate analysis was performed with non-conditional bivariate logistic regression to identify the underlying factors of vaccination recommendations. Subsequent information regarding the following vaccination and the occurrence of AEFI were also collected and analyzed. Results: The main diseases consulted were those relating to the circulatory and nervous systems as well as neonatal diseases. The distribution of diseases varied by age: 53.6% infants under 12 months were counseled for circulatory system diseases, while 44.6% children aged 12~24 months and 54.7% children over 25 months were counseled for nervous system diseases. According to the evaluation reports issued by the consultation clinic, 75.0% of CSHCN were recommended to be vaccinated normally, 21.2% were recommended to defer specific vaccination, while only 3.8% were recommended to defer all vaccinations. In logistic regression analysis, age, history of adverse events following immunization (AEFI) and the number of diseases combined were all strong correlative factors for vaccination recommendations. Children who were aged over 25-month-old (OR = 1.34, 95%CI: 1.11-1.61) or had a history of AEFI (OR = 3.77, 95%CI: 2.83~5.01) or those who had numerous diseases combined (OR = 2.00, 95%CI: 1.46~2.75) tended to have a higher rate of deferred vaccination recommendation. Among those CSHCN who received nationally-recommended vaccines, the estimated AEFI rate was 24.29/100 000. No uncommon or rare serious adverse reactions were detected. Conclusion: Age, history of AEFI, and the number of diseases combined were important factors that affected the vaccination recommendations of CSHCN. Most CSHCN can be safely vaccinated according to the nationally-recommended schedule.

Risk of seizures after immunization in children with epilepsy: a risk interval analysis

BACKGROUND

In children with epilepsy, fever and infection can trigger seizures. Immunization can also induce inflammation and fever, which could theoretically trigger a seizure. The risk of seizure after immunization in children with pre-existing epilepsy is not known. The study objective was to determine the risk of medically attended seizure after immunization in children with epilepsy < 7 years of age.

METHODS

We conducted a retrospective study of children < 7 years of age with epilepsy in Nova Scotia, Canada from 2010 to 2014. Hospitalizations, emergency visits, unscheduled clinic visits, and telephone calls for seizures were extracted from medical records. Immunization records were obtained from family physicians and Public Health with informed consent. We conducted a risk interval analysis to estimate the relative risk (RR) of seizure during risk periods 0-14, 0-2, and 5-14 days post-immunization versus a control period 21-83 days post-immunization.

RESULTS

There were 302 children with epilepsy who were eligible for the study. Immunization records were retrieved on 147 patients (49%), of whom 80 (54%) had one or more immunizations between the epilepsy diagnosis date and age 7 years. These 80 children had 161 immunization visits and 197 medically attended seizures. Children with immunizations had more seizures than either those with no immunizations or those with no records (mean 2.5 versus 0.7 versus 0.9, p < 0.001). The risk of medically attended seizure was not increased 0-14 days after any vaccine (RR = 1.1, 95% confidence interval (CI): 0.5-2.8) or 0-2 days after inactivated vaccines (RR = 0.9, 95% CI: 0.1-7.1) versus 21-83 days post-immunization. No seizure events occurred 5-14 days after live vaccines.

CONCLUSIONS

Children with epilepsy do not appear to be at increased risk of medically attended seizure following immunization. These findings suggest that immunization is safe in children with epilepsy, with benefits outweighing risks.

Mortality in Dravet syndrome: A review

INTRODUCTION

Premature mortality is a major issue in Dravet syndrome (DS). To improve understanding of DS premature mortality, we conducted a comprehensive literature search with a particular emphasis on SUDEP.

METHODS

We searched PubMed, Embase, Web of Science, Cochrane, CENTRAL, CINAHL, PsycINFO, Academic Search Premier, and ScienceDirect on the following terms: "Dravet syndrome", "severe myoclonic epilepsy", "SMEI", "mortality", "survivors", "prognosis", and "death". DS cases or cohorts studies reporting mortality were included.

RESULTS

The search yielded 676 articles and 86 meeting abstracts. After removing duplicates and screening titles and abstracts, full text of 73 articles was reviewed. Only 28 articles and six meeting abstracts met inclusion criteria. Five articles and four meeting abstracts were excluded, as the case(s) were also described elsewhere. After checking the references, five additional studies were included. The 30 items reported 177 unique cases. Sudden unexpected death in epilepsy was the likely cause in nearly half of the cases (n=87, 49%), followed by status epilepticus (n=56, 32%). Drowning or accidental death was reported in 14 cases (8%), infections in 9 (5%), other causes in six (3%), and unknown in five (3%). Age at death was reported for 142 of the 177 cases (80%), with a mean age of 8.7±9.8years (SD); 73% died before the age of 10years.

DISCUSSION

Dravet syndrome is characterized by high epilepsy-related premature mortality and a marked young age at death. Sudden unexpected death in epilepsy is the leading reported cause of death in DS, accounting for nearly half of all deaths. The cause of this excess mortality remains elusive but may be explained by epilepsy severity, as well as genetic susceptibility to SUDEP.

Vaccinations and Dravet Syndrome

Investigators from various university hospitals, reference medical institutions and epilepsy centers, and the national institute for public health and environment in the Netherlands, studied the effect of vaccinations on seizure risk and disease course in patients with Dravet syndrome (DS).