Childhood vaccines and Kawasaki disease, Vaccine Safety Datalink, 1996-2006

Risk of Kawasaki Disease/Multisystem Inflammatory Syndrome Following COVID-19 Vaccination in Korean Children: A Self-Controlled Case Series Study

BACKGROUND

Rare cases of Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) have been reported following the coronavirus disease 2019 (COVID-19) vaccination; however, the association between COVID-19 vaccination and the risk of developing KD/MIS-C has not yet been established.

METHODS

We conducted a self-controlled case series analysis using a large-linked database that connects the COVID-19 immunization registry with nationwide claims data. We identified individuals aged < 18 years who received their initial COVID-19 vaccination and had a KD/MIS-C diagnosis with a prescription for intravenous immunoglobulin or corticosteroids between October 18, 2021, and April 15, 2023. The observation period was set as 240 days from the date of the COVID-19 vaccination. The risk window was 60 days after vaccination, with the remaining observation period serving as the control window. The incidence rate ratios (IRRs) and 95% confidence intervals (CIs) in the risk versus control windows were estimated using the conditional Poisson regression model. We further analyzed the vaccine doses and types for secondary analysis. We also performed subgroup analyses stratified by sex, age, comorbidities, and other conditions and sensitivity analyses by varying the length of the risk window and outcome definition.

RESULTS

Among 2,369,490 individuals who received the COVID-19 vaccination, 12 cases of KD/MIS-C were identified, which included five and seven patients in the risk and control windows, respectively. There was no increased risk of KD/MIS-C within the 60-day period of vaccination (IRR, 0.53; 95% CI, 0.17-1.60). Secondary subgroup and sensitivity analyses showed no significant increase in the risk of KD/MIS-C after COVID-19 vaccination, which is consistent with the results of the main analysis.

CONCLUSION

The results of this nationwide study suggest that the risk of developing KD/MIS-C did not increase after COVID-19 vaccination. However, owing to the lack of a sufficient number of cases, future studies utilizing multinational long-term follow-up databases should be conducted. Considering the increasing incidence of KD/MIS-C and the limited understanding of its precise biological mechanisms, additional research on KD/MIS-C is warranted.

Atypical Kawasaki disease with giant coronary artery aneurysms in a 2-month-old boy: a case report

BACKGROUND

Kawasaki disease is an acute inflammatory disorder primarily affecting medium-sized blood vessels, especially in infants and young children under 5 years old, characterized by inflammation of the arterial walls, including coronary arteries. While predominantly affecting young children, rarely Kawasaki disease is seen in adults. Reporting this case is crucial due to the patient's very young age and the disease's unusual presentation following vaccination, contributing to the limited literature on Kawasaki disease in very young infants.

CASE PRESENTATION

A full-term, 2-month-and-10-day-old Iranian boy presented with persistent fever unresponsive to treatment, beginning 5 days after receiving the 5-in-1 vaccine. Although physical examination results were normal, his medical history included maternal hypothyroidism during pregnancy and neonatal jaundice that did not require hospitalization. Initial laboratory tests revealed bicytopenia, thrombocytosis on the complete blood count, and elevated erythrocyte sedimentation rate and C-reactive protein levels. Echocardiography identified giant coronary artery aneurysms. The patient was diagnosed with atypical Kawasaki disease and treated with intravenous immunoglobulin, methylprednisolone, infliximab, and aspirin, which resolved his fever.

CONCLUSIONS

This case emphasizes the importance of considering Kawasaki disease as a differential diagnosis in infants with persistent, treatment-resistant fever and abnormal complete blood count findings. Early diagnosis and timely intervention are essential to prevent severe complications, such as coronary artery aneurysms and possible mortality. It underscores the need for heightened awareness and vigilance among healthcare providers in similar clinical scenarios.

Case Series on the Efficacy and Safety of Tocilizumab in IVIG-Resistant Kawasaki Disease: A Retrospective Analysis of Five Patients

Background

Kawasaki disease (KD) is a leading cause of acquired heart disease in children in developed countries. While intravenous immunoglobulin (IVIG) is the standard treatment, 10-20% of patients do not respond to IVIG. Given the significant role of interleukin-6 (IL-6) in KD pathophysiology, targeting IL-6 may offer a therapeutic option for IVIG-resistant KD.

Objective

This study aims to evaluate the efficacy and safety of tocilizumab (an IL-6 receptor antagonist) in the treatment of IVIG-resistant KD through a retrospective analysis of clinical data.

Methods

Clinical data from five KD patients treated with tocilizumab (TCZ) at Jiangxi Children's Hospital from January 2023 to February 2024 were retrospectively analyzed. All patients met the 2017 American Heart Association diagnostic criteria for KD and received a single dose of TCZ. Data on clinical manifestations, laboratory indicators, and coronary artery changes before and after TCZ treatment were collected.

Results

Four of the five patients had a KOBAYASHI score >4, and initial IVIG and glucocorticoid treatments were ineffective. Following TCZ administration, body temperature normalized within 12 hours in three patients, and inflammatory markers, including C-reactive protein and interleukin-6, returned to normal levels. Coronary artery dilation was observed in 75% of patients pre-TCZ; post-TCZ, coronary arteries normalized in three patients, while one patient experienced progressive right coronary artery dilation. No adverse events were reported following TCZ administration.

Conclusion

Tocilizumab effectively controls systemic inflammation and improves coronary artery outcomes in IVIG-resistant KD patients, with no observed adverse events. Larger studies are necessary to confirm these findings and further investigate long-term effects on coronary artery health.

Profiling humoral responses to COVID-19 immunization in Kawasaki disease using SARS-CoV-2 variant protein microarrays

Kawasaki disease (KD) is a form of acute systemic vasculitis syndrome that predominantly occurs in children under the age of 5 years. Its etiology has been postulated due to not only genetic factors but also the presence of foreign antigens or infectious agents. To evaluate possible associations between Kawasaki disease (KD) and COVID-19, we investigated humoral responses of KD patients against S-protein variants with SARS-CoV-2 variant protein microarrays. In this study, plasma from a cohort of KD (N = 90) and non-KD control (non-KD) (N = 69) subjects in categories of unvaccinated-uninfected (pre-pandemic), SARS-CoV-2 infected (10-100 days after infection), and 1-dose, 2-dose, and 3-dose BNT162b2 vaccinated (10-100 days after vaccination) was collected. The principal outcomes were non-KD-KD differences for each category in terms of anti-human/anti-His for binding antibodies and neutralizing percentage for surrogate neutralizing antibodies. Binding antibodies against spikes were lower in the KD subjects with 1-dose of BNT162b2, and mean differences were significant for the P.1 S-protein (non-KD-KD, 3401; 95% CI, 289.0 to 6512; P = 0.0252), B.1.617.2 S-protein (non-KD-KD, 4652; 95% CI, 215.8 to 9087; P = 0.0351) and B.1.617.3 S-protein (non-KD-KD, 4874; 95% CI, 31.41 to 9716; P = 0.0477). Neutralizing antibodies against spikes were higher in the KD subjects with 1-dose of BNT162b2, and mean percentage differences were significant for the 1-dose BNT162b2 B.1.617.3 S-protein (non-KD-KD, -22.89%; 95% CI, -45.08 to -0.6965; P = 0.0399), B.1.1.529 S-protein (non-KD-KD, -25.96%; 95% CI, -50.53 to -1.376; P = 0.0333), BA.2.12.1 S-protein (non-KD-KD, -27.83%; 95% CI, -52.55 to -3.115; P = 0.0195), BA.4 S-protein (non-KD-KD, -28.47%; 95% CI, -53.59 to -3.342; P = 0.0184), and BA.5 S-protein (non-KD-KD, -30.42%; 95% CI, -54.98 to -5.869; P = 0.0077). In conclusion, we have found that KD patients have a comparable immunization response to healthy individuals to SARS-CoV-2 infection and COVID-19 immunization.

Evaluating the use of methods to mitigate bias from non-transient medications in the case-crossover design: A systematic review

PURPOSE

The case-crossover design is a self-controlled study design used to compare exposure immediately preceding an event occurrence with exposure in earlier control periods. The design is most suitable for transient exposures in order to avoid biases that can be problematic when using the case-crossover design for non-transient (i.e., chronic) exposures. Our goal was to conduct a systematic review of case-crossover studies and its variants (case-time-control and case-case-time-control) in order to compare design and analysis choices by medication type.

METHODS

We conducted a systematic search to identify recent case-crossover, case-time-control, and case-case-time-control studies focused on medication exposures. Articles indexed in MEDLINE and EMBASE using these study designs that were published between January 2015 and December 2021 in the English language were identified. Reviews, methodological studies, commentaries, articles without medications as the exposure of interest, and articles with no available full text were excluded. Study characteristics including study design, outcome, risk window, control window, reporting of discordant pairs, and inclusion of sensitivity analyses were summarized overall and by medication type. We further evaluated the implementation of recommended methods to account for biases introduced by non-transient exposures among articles that used the case-crossover design on a non-transient exposure.

RESULTS

Of the 2036 articles initially identified, 114 articles were included. The case-crossover was the most common study design (88%), followed by the case-time-control (17%), and case-case-time-control (3%). Fifty-three percent of the articles included only transient medications, 35% included only non-transient medications, and 12% included both. Across years, the proportion of case-crossover articles evaluating a non-transient medication ranged from 30% in 2018 to 69% in 2017. We found that 41% of the articles that evaluated a non-transient medication did not apply any of the recommended methods to account for biases and more than half of which were conducted by authors with no previous publication history of case-crossover studies.

CONCLUSION

Using the case-crossover design to evaluate a non-transient medication remains common in pharmacoepidemiology. Researchers should apply appropriate design and analysis choices when opting to use a case-crossover design with non-transient medication exposures.

Research trends on causes of Kawasaki disease in the COVID-19 era: focus on viral infections

Despite studies on the etiology of Kawasaki disease (KD) ongoing for half a century since its discovery, its cause has not yet been clearly identified. Although the clinical, epidemiological, and pathophysiological characteristics of KD are presumed to be closely related to infectious diseases, studies of various pathogens to identify its etiology have been actively conducted. To date, bacteria, fungi, and viruses have been investigated to determine the relationship between KD and infection, among which viruses have attracted the most attention. In particular, during the coronavirus disease 2019 pandemic, there were many reports in Europe of a sharp increase in cases of Kawasaki-like disease (KLD), while conflicting reports that the prevalence of KD decreased due to thorough "social distancing" or "wearing mask" in Asian countries drew more attention regarding the association between KD and viral infection. Therefore, the differential diagnosis of KD from KLD with these similar spectra has become a very important issue; simultaneously, research to solve questions about the association between KD and viral infections, including sudden acute respiratory syndrome coronavirus 2, is drawing attention again. Moreover, a new concept has emerged that immune responses occurring in patients with KD can be caused by the pathogen itself as well as host cells damaged by infection. This paper summarizes the research trends into KD etiology and related pathophysiology, especially its association with viral infections, and present future research tasks to increase our understanding of KD.

Kawasaki Disease Following the 13-valent Pneumococcal Conjugate Vaccine and Rotavirus Vaccines

BACKGROUND

Temporal associations between Kawasaki disease (KD) and childhood vaccines have been reported. Limited data on KD following 13-valent pneumococcal conjugate (PCV13) and rotavirus vaccines are available.

METHODS

We conducted a self-controlled risk interval study using Vaccine Safety Datalink electronic health record data to investigate the risk of KD following PCV13 and rotavirus vaccines in children <2 years of age who were born from 2006 to 2017. All hospitalized KD cases identified by International Classification of Diseases diagnosis codes that fell within predefined risk (days 1-28 postvaccination) and control (days 29-56 for doses 1 and 2, and days 43-70 for doses 3 and 4) intervals were confirmed by manual chart review.

RESULTS

During the study period, 655 cases of KD were identified by International Classification of Diseases codes. Of these, 97 chart-confirmed cases were within risk or control intervals. In analyses, the age-adjusted relative risk for KD following any dose of PCV13 was 0.75 (95% confidence interval, 0.47-1.21). Similarly, the age-adjusted relative risk for KD following any dose of rotavirus vaccine was 0.66 (95% CI, 0.40-1.09). Overall, there was no evidence of an elevated risk of KD following PCV13 or rotavirus vaccines by dose. In addition, no statistically significant temporal clustering of KD cases was identified during days 1 to 70 postvaccination.

CONCLUSIONS

PCV13 and rotavirus vaccination were not associated with an increased risk of KD in children <2 years of age. Our findings provide additional evidence for the overall safety of PCV13 and rotavirus vaccines.

Kawasaki disease following immunization reported to the Canadian Immunization Monitoring Program ACTive (IMPACT) from 2013 to 2018

Kawasaki disease (KD) is an acute systemic vasculitis primarily affecting children younger than 5 y of age that has been reported as an adverse event following immunization (AEFI). The Canadian Immunization Monitoring Program ACTive (IMPACT) conducts active surveillance for KD following immunization across Canada. We characterized KD cases reported to IMPACT between 2013 and 2018. Cases admitted to an IMPACT hospital with a physician diagnosis of complete or incomplete KD with onset 0–42 d following vaccination were reviewed. Cases meeting the Brighton Collaboration case definition (BCCD) levels of diagnostic certainty levels 1 a/b, 2a/b or 3a-e were defined as KD cases. Demographic and vaccination characteristics were compared between KD cases and non-cases. Of 84 cases reviewed, 58 met the BCCD: 47 (81%) cases met level 1a (Complete KD), 8 (14%) met level 1b (Incomplete KD), 2 (3%) met level 2a, and 1 (2%) met level 2c (Probable KD). Median age at admission was 13 months (interquartile range 7–26 months). A median of 9.5 cases were reported per year (range 4–14). Thirty-one (53%) KD cases were temporally associated with diphtheria-tetanus acellular pertussis containing vaccinations, followed by 21 (36%) cases with pneumococcal conjugate vaccines. Symptom onset was 0–14 d after vaccination in 32 (55%) cases. Echocardiogram results were available for 43 (74%) cases with 22 reported as abnormal. Age, sex, interval to symptom onset, and vaccines received were similar between KD cases and non-cases. No safety signals were detected in these data.

Cytokine Cascade in Kawasaki Disease Versus Kawasaki-Like Syndrome

Kawasaki disease (KD) is a medium vessel systemic vasculitis that predominantly occurs in children below five years of age. It is an acute febrile condition in which coronary artery aneurysms and myocarditis are the most common cardiovascular complications. It is most often characterized by hypercytoki-nemia. The etiopathogenesis of KD is not fully understood. The present review synthesizes the recent advances in the pathophysiology and treatment options of KD. According to different studies, the genetic, infections and autoimmunity factors play a major role in pathogenesis. Several susceptibility genes (e.g. caspase 3) and cytokines (e.g. IL-2, IL-4, IL-6, IL-10, IFN-γ and TNF-α) have been identified in KD. Patients with high cytokine levels are predisposed to KD shock syndrome. The importance of respiratory viruses in the pathogenesis of the disease is unclear. Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may induce in children and adults an abnormal systemic inflammatory response. This syndrome shares characteristics with KD. It has been called by many terms like MIS-C (Multisystem Inflammatory Syndrome in Children), PIMS-TS (pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2), hyperinflammatory shock syndrome, cytokine storm (cytokine release syndrome) or simply, Kawasaki-like syndrome. The cytokine’s role in the development of KD or Kawasaki-like syndrome being triggered by COVID-19 is controversial. The presences of the antiendothelial cell autoantibodies (AECAs) together with the newly developed hypothesis of immunothrombosis are considered potential pathogenic mechanisms for KD. In consequence, the diagnosis and treatment of KD and Kawasaki-like syndrome, one of the most common causes of acquired heart disease in developed countries, are challenging without a clearly defined protocol.

Hygiene Hypothesis as the Etiology of Kawasaki Disease: Dysregulation of Early B Cell Development

Kawasaki disease (KD) is an acute systemic vasculitis that occurs predominantly in children under 5 years of age. Despite much study, the etiology of KD remains unknown. However, epidemiological and immunological data support the hygiene hypothesis as a possible etiology. It is thought that more sterile or clean modern living environments due to increased use of sanitizing agents, antibiotics, and formula feeding result in a lack of immunological challenges, leading to defective or dysregulated B cell development, accompanied by low IgG and high IgE levels. A lack of B cell immunity may increase sensitivity to unknown environmental triggers that are nonpathogenic in healthy individuals. Genetic studies of KD show that all of the KD susceptibility genes identified by genome-wide association studies are involved in B cell development and function, particularly in early B cell development (from the pro-B to pre-B cell stage). The fact that intravenous immunoglobulin is an effective therapy for KD supports this hypothesis. In this review, I discuss clinical, epidemiological, immunological, and genetic studies showing that the etiopathogenesis of KD in infants and toddlers can be explained by the hygiene hypothesis, and particularly by defects or dysregulation during early B cell development.

Kawasaki Disease and Vaccination: Prospective Case-Control and Case-Crossover Studies among Infants in Japan

The causal effects of vaccines on Kawasaki disease (KD) remain elusive. We aimed to examine the association between vaccines administered during infancy and the development of KD in Japan. We conducted a multicenter prospective case-control study using questionnaires and compared the vaccination status of infants (age: 6 weeks to 9 months) who developed KD (KD group; n = 102) and those who did not develop KD (non-KD group; n = 139). Next, we performed a case-crossover study of 98 cases in the KD group and compared the status of vaccinations between the case and control periods. We also compared the incidence of KD in children for each 5-year period before and after the addition of new vaccines (2012–2013) using data from the Nationwide Survey of KD. In the case-control study, the vaccination status of the KD and control groups did not differ to a statistically significant extent. Multivariable analysis of the vaccination status and patient backgrounds showed no significant association between vaccination and KD development. In the case-crossover study, the status of vaccinations during the case and control periods did not differ to a statistically significant extent. In the analysis of data from the Nationwide Survey of KD, the incidence of KD in children of ages subject to frequent vaccination showed no significant increases in the latter five years, 2014–2018. Based on these prospective analyses, we confirmed that vaccination in early infancy did not affect the risk of KD.

U.S. Population-Based background incidence rates of medical conditions for use in safety assessment of COVID-19 vaccines

The Coronavirus Disease 2019 (COVID-19) pandemic has had a devastating impact on global health, and has resulted in an unprecedented, international collaborative effort to develop vaccines to control the outbreak, protect human lives, and avoid further social and economic disruption. Mass vaccination campaigns are underway in multiple countries and are expected worldwide once more vaccine becomes available. Some early candidate vaccines use novel platforms, such as mRNA encapsulated in lipid nanoparticles, and relatively new platforms, such as replication-deficient viral vectors. While these new vaccine platforms hold promise, limited safety data in humans are available. Serious health outcomes linked to vaccinations are rare, and some outcomes may occur incidentally in the vaccinated population. Knowledge of background incidence rates of these medical conditions is a critical component of vaccine safety monitoring to aid in the assessment of adverse events temporally associated with vaccination and to put these events into context with what would be expected due to chance alone. A list of 22 potential adverse events of special interest (AESI), including neurologic, autoimmune, and cardiovascular disorders, was compiled by subject matter experts at the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention. The most recently available U.S. background rates for these medical conditions, overall and by age, sex, and race/ethnicity (when available), were sourced from reported statistics (data published by medical panels/ associations or federal government reports), and literature reviews in PubMed. This review provides estimates of background incidence rates for medical conditions that may be monitored or studied as AESI during safety surveillance and research for COVID-19 vaccines and other new vaccines.

Acute and chronic inflammatory neuropathies and COVID-19 vaccines: Practical recommendations from the task force of the Italian Peripheral Nervous System Association (ASNP)

BACKGROUND AND AIMS

To develop recommendations for vaccination for coronavirus-19 (COVID-19) in patients with inflammatory neuropathies.

METHODS

Key questions were formulated in order to perform a literature review on the safety and efficacy of vaccines in patients with inflammatory neuropathies. Based on the best evidence and expert opinion, a list of recommendations was formulated to inform decision on vaccination for COVID-19 in patients with inflammatory neuropathies and increase adherence to vaccination programmes.

RESULTS

Recommendations addressing safety and efficacy of vaccination in patients with inflammatory neuropathies were formulated. No data are currently available on the safety and efficacy of COVID-19 vaccines in patients with inflammatory neuropathies or other immune-mediated conditions. There is only sparse data on the safety of previous available vaccines in patients with inflammatory neuropathies, but studies on other autoimmune disorders indicate that these are safe and mostly efficacious. Patients with inflammatory neuropathies might be at increased risk for severe illness from COVID-19.

INTERPRETATION

Patients with inflammatory neuropathies should be encouraged to adhere to the vaccination campaign for COVID-19. These recommendations provide guidance on the management of vaccinations for COVID-19 in patients with inflammatory neuropathies. More research is needed regarding the safety and efficacy of vaccination in patients with inflammatory neuropathies and other immune conditions.

Kawasaki disease: Shedding light on a mysterious diagnosis

Kawasaki disease is an acute systemic febrile vasculitis of medium and small arteries, most often occurring in children under age 5 years. This condition is the most common cause of acquired heart disease in children in the developed world. The cause is unclear but is thought to be a hyperimmune reaction to an infectious agent. Diagnosis is clinical; the classic presentation includes persistent fever, lymphadenopathy, oral mucosal changes, conjunctivitis, and rash. Although the disease technically is self-limiting, treatment with IV immunoglobulin (IVIG) and high-dose aspirin is necessary to prevent cardiac complications, such as coronary artery aneurysm, pericarditis, or myocarditis. This article reviews the pathophysiology, clinical presentation, diagnosis, and treatment of Kawasaki disease.

Kawasaki Disease: an Update

PURPOSE OF REVIEW

Provide the most recent updates on the epidemiology, pathogenesis, and treatment advances in Kawasaki disease.

RECENT FINDINGS

Treatment advances in complex, IVIG-refractory cases of Kawasaki disease. Multisystem inflammatory syndrome, a newly reported inflammatory condition with Kawasaki-like features and an association with the 2019 Coronavirus (COVID-19). Kawasaki disease (KD) is a rare systemic inflammatory disease that predominately affects children less than 5 years of age. Pathogenesis of KD remains unknown; the leading theory is that an unknown stimulus triggers an immune-mediated inflammatory cascade in a genetically susceptible child. Classic KD is a clinical diagnosis based on set criteria and excluding other similar clinical entities. Patients who do not fulfill complete diagnostic criteria for KD are often referred to as atypical (or incomplete) KD. The most feared complication of KD is coronary artery abnormality development, and patients with atypical KD are also at risk. Administration of intravenous immunoglobulin (IVIG) and aspirin has greatly reduced the incidence of coronary lesions in affected children. Several other immune-modulating therapies have recently been utilized in complex or refractory cases.

Intussusception and Kawasaki disease after rotavirus vaccination in Taiwanese infants

BACKGROUND

Since 2006, two rotavirus vaccines have been licensed in Taiwan, either as a 2- (RV1) or 3-dose (RV5) schedule administered at ages 2, 4, and 6 months. This study assessed the risk of intussusception and Kawasaki disease (KD) associated with rotavirus vaccines among infants.

METHODS

Cases of intussusception and KD in infants aged less than 365 days were identified from the National Health Insurance databases, from 1 January 2007 through 31 December 2014, using the first-ever ICD-9-CM diagnosis codes. Histories of rotavirus vaccination were obtained from the National Immunization Information System. The modified self-controlled case series design included vaccinated cases, and compared incidence rate ratios (IRRs) between the risk period (postvaccination days 1-21 [intussusception] or days 1-28 [KD]) and control period (ages 0-364 days outside the -14 to +21 [intussusception] or +28 [KD] days of vaccination) by each type and dose of vaccine. Conditional Poisson regression models were adjusted for age using age-in-week (7-day) categorization.

RESULTS

Overall 2064 intussusception cases and 2079 KD cases were diagnosed in 567,726 recipients (5313 [0.9%] received both RV5 and RV1). An increase in intussusception risk was observed in the 1-7 days (IRR 12.59, 95% confidence interval [CI] 8.07-19.66) and 8-21 days (IRR 1.78, 95% CI 1.00-3.16) post dose 1 of RV1, but not RV5. Risk of KD was higher during the third week post dose 2 of RV5 (IRR 2.33, 95% CI 1.35-4.00), and fourth week post dose 1 of RV1 (IRR 1.98, 95% CI 1.16-3.40).

CONCLUSION

Our finding of an increased risk of intussusception associated with RV1 in the first week after dose 1 is consistent with results of previous postlicensure studies. Further research should verify a potentially delayed risk of KD after rotavirus vaccination.

A framework for understanding Kawasaki disease pathogenesis

Kawasaki disease (KD) is a common vasculitis of childhood, typically affecting children under the age of five. Despite many aspects of its presentation that bear resemblence to acute infection, no causative infectious agent has been identified despite years of intense scrutiny. Unlike most infections, however, there are significant differences in racial predilection that suggest a strong genetic influence. The inflammatory response in KD specifically targets the coronary arteries, also unusual for an infectious condition. In this review, we discuss recent hypotheses on KD pathogenesis as well as new insights into the innate immune response and mechanisms behind vascular damage. The pathogenesis is complex, however, and remains inadequately understood.

Kawasaki Disease and the Use of the Rotavirus Vaccine in Children: A Systematic Review and Meta-Analysis

Background: The vaccine against the rotavirus is an effective measure in reducing hospitalizations and mortality caused by the virus. However, its use can result in serious adverse effects. The available evidence on Kawasaki disease has not yet been reported in the literature. This study investigated the risk of developing Kawasaki disease with the use of rotavirus vaccines in children. Methods: This is a systematic review of data collected from studies retrieved on the following databases: Cochrane, MEDLINE, Embase, CINAHL, Scopus, Web of Science, HealthSTAR, Lilacs, Clinical trial.gov, and International Clinical Trials Registry Platform, up to the 15th of August 2018, with no restrictions on language or date of publication. The outcomes measured were incidence of Kawasaki disease, risk of developing the disease, and rate of discontinuation of the vaccination schedule. Four reviewers independently selected the studies, performed data extraction, and assessed the quality of evidence. A meta-analysis of random effects was performed. Results: A total of 13 publications were included, with a population of 164,434 children included in the meta-analysis. The incidence of Kawasaki disease (24 cases per 100,000, 95% CI = 11.98-48.26) in the vaccinated children was low. No difference between the vaccines was found in the prevalence rate of adverse effects (RR = 1.55, 95% CI = 0.41-5.93). Use of the vaccines was not associated with risk of developing Kawasaki disease (low-quality evidence). None of the studies reported the rate of discontinuation of the vaccination schedule. Conclusions: The vaccines were associated with a low incidence of developing Kawasaki disease, showing no association with this serious adverse effect.

Update on association between Kawasaki disease and infection

The relationship between infection and Kawasaki disease (KD) remains unclear. Infection has long been considered a key predisposing factor for KD. Bacterial and viral agents may be related to the onset of KD because of superantigen and cytokine production. Various bacterial and viral infections have been reported to be associated with KD, but the actual mechanism remains unknown. The higher association between KD and enterovirus has been well documented by using Taiwan National Health Insurance Research Database. However, no evidence has been obtained that various bacterial and viral infections induce KD. Comprehensive research, including infectious agents, should be conducted to elucidate the pathogenesis of KD.

Demonstration of background rates of three conditions of interest for vaccine safety surveillance

INTRODUCTION

Adverse events following immunization (AEFIs) are unwanted or unexpected health outcomes following vaccination, which may or may not be causally-linked to vaccines. AEFI reporting is important to post-marketing vaccine safety surveillance and has the potential to identify new or rare AEFIs, show increases in known AEFIs, and help to maintain public confidence in vaccine programs. Knowledge of the expected incidence (i.e. background rate) of a possible AEFI is essential to the investigation of vaccine safety signals. We selected three rarely reported AEFIs representing the spectrum of causal association with vaccines, from proven (immune thrombocytopenia [ITP]) to questioned (Kawasaki disease [KD]) to unsubstantiated (multiple sclerosis [MS]) and determined their background rates.

METHODS

We extracted data on hospitalizations (CIHI Discharge Abstract Database) for ITP, KD, and MS among Ontario children for the period 2005 to 2014 from IntelliHEALTH. As ITP can be managed without hospitalization, we also extracted emergency department (ED) visits from the CIHI National Ambulatory Care Reporting System. For all conditions, we only counted the first visit and if the same child had both an ED visit and a hospitalization for ITP, only the hospitalization was included. We calculated rates by year, age group and sex using population estimates from 2005-2014, focusing on age groups within the Ontario immunization schedule around vaccine(s) of interest.

RESULTS

Per 100,000 population, annual age-specific incidence of ITP in children age 1 to 7 years ranged from 8.9 to 12.2 and annual incidence of KD in children less than 5 years ranged from 19.1 to 32.1. Average annualized incidence of adolescent (11-17 years) MS across the study period was 0.8 per 100,000.

DISCUSSION

Despite limitations, including lack of clinical validation, this study provides an example of how health administrative data can be used to determine background rates which may assist with interpretation of passive vaccine safety surveillance.

Kawasaki disease: guidelines of the Italian Society of Pediatrics, part I - definition, epidemiology, etiopathogenesis, clinical expression and management of the acute phase

The primary purpose of these practical guidelines related to Kawasaki disease (KD) is to contribute to prompt diagnosis and appropriate treatment on the basis of different specialists' contributions in the field. A set of 40 recommendations is provided, divided in two parts: the first describes the definition of KD, its epidemiology, etiopathogenetic hints, presentation, clinical course and general management, including treatment of the acute phase, through specific 23 recommendations.Their application is aimed at improving the rate of treatment with intravenous immunoglobulin and the overall potential development of coronary artery abnormalities in KD. Guidelines, however, should not be considered a norm that limits treatment options of pediatricians and practitioners, as treatment modalities other than those recommended may be required as a result of peculiar medical circumstances, patient's condition, and disease severity or complications.

Kawasaki disease and vasculitis associated with immunization

The etiology and pathogenesis of Kawasaki disease (KD) remain poorly understood. Among the diverse infectious and environmental factors examined to be triggers for, or be associated with, KD, are immunizations. In this report, we first describe the case of a Caucasian girl who presented with classic KD shortly after receiving her routine 4 months vaccination series. Prior published case reports and large epidemiological studies, which explore potential associations between immunization and KD and other vasculitides, are then comprehensively reviewed. The methodologic challenges that complicate analysis in this area are also considered.

An infant presenting with Kawasaki disease following immunization for influenza: A case report

Kawasaki disease (KD) is a childhood vascular disorder of unknown etiology. Concerns have recently been raised regarding vaccinations as a potential risk factor for KD. In addition, various forms of vasculitis have been reported as adverse events following administration after various vaccines. Patients exhibiting post vaccination KD have previously been described; however, thus far, to the best of our knowledge, only one patient exhibiting post influenza vaccination KD has been reported in Japan. The present study describes a case of KD 24 h after immunization with influenza in an infant (age, 18 months) following 6 days of high fever, a body rash that had persisted for 2 days and nonsuppurative bilateral conjunctivitis. To the best of the authors' knowledge, this is the first reported case in Korea and the present study reviews various recent studies regarding vasculitis following vaccination and the causal association between them.

Kawasaki disease and immunisation: A systematic review

BACKGROUND

Kawasaki disease is a complex and potentially serious condition. It has been observed in temporal relation to immunisation.

METHODS

We conducted a systematic literature review using various reference sources to review the available evidence published in the literature.

RESULTS

We identified twenty seven publications reporting a temporal association between immunisation and Kawasaki disease. We present a systematic review of data drawn from randomised controlled trials, observational studies, case series and reports, and reviews. Overall there was a lack of standardised case definitions, making data interpretation and comparability challenging.

CONCLUSIONS

Although a temporal relationship between immunisation and Kawasaki disease is suggested, evidence for an increased risk or a causal association is lacking. Implementation of a standardised Kawasaki disease case definition would increase confidence in the findings and add value to future studies of pre- or post-licensure vaccine safety studies.

Two infants with tuberculid associated with Kawasaki disease

Bacille de Calmette et Guerin (BCG) is the only licensed tuberculosis vaccine to prevent severe tuberculosis. The adverse events of BCG vaccination, including local reactions, lymphadenitis, osteomyelitis, tuberculid, and disseminated infection, have been reported. Two infants presented erythema at the inoculation site of BCG after the resolution of Kawasaki disease (K_D). They received BCG vaccination 1 week and 6 weeks before the K_D onset, respectively. Intravenous immunoglobulin improved the K_D activity, however the skin rash of BCG inoculation site extended to the face and extremities days 24 and 10 after the K_D onset, respectively. Both bacteriological study and interferon-γ release assay were negative for Mycobacterium tuberculosis infection. These patients were diagnosed as having tuberculid after K_D. The skin lesions gradually disappeared without antibiotic therapy over 2 months. The development of tuberculid in these patients might be associated with the remnant immune activation of K_D.

Vaccines and Kawasaki disease

The distinctive immune system characteristics of children with Kawasaki disease (KD) could suggest that they respond in a particular way to all antigenic stimulations, including those due to vaccines. Moreover, treatment of KD is mainly based on immunomodulatory therapy. These factors suggest that vaccines and KD may interact in several ways. These interactions could be of clinical relevance because KD is a disease of younger children who receive most of the vaccines recommended for infectious disease prevention. This paper shows that available evidence does not support an association between KD development and vaccine administration. Moreover, it highlights that administration of routine vaccines is mandatory even in children with KD and all efforts must be made to ensure the highest degree of protection against vaccine-preventable diseases for these patients. However, studies are needed to clarify currently unsolved issues, especially issues related to immunologic interference induced by intravenous immunoglobulin and biological drugs.

Spontaneous reports of vasculitis as an adverse event following immunization: A descriptive analysis across three international databases

BACKGROUND

Vasculitides have been reported as adverse events following immunization (AEFI) following various vaccines. We describe reports of vasculitis to three international spontaneous reporting systems.

METHODS

All spontaneous reports of vasculitis following immunization between January 2003 and June 2014 were retrieved from Eudravigilance (EV), the Vaccine Adverse Event Reporting System (VAERS), and VigiBase^®. A Standard MedDRA Query (SMQ) for vasculitis was used and vaccine types were categorized using the Anatomical Therapeutic Chemical classification system. We performed a descriptive analysis by source, sex, age, country, time to onset, vaccine, and type of vasculitis.

RESULTS

We retrieved 1797 reports of vasculitis in EV, 1171 in VAERS, and 2606 in VigiBase^®. Vasculitis was predominantly reported in children aged 1-17 years, and less frequently in the elderly (>65 years). The generic term "vasculitis" was the most frequently reported AEFI in this category across the three databases (range 21.9% to 27.5% of all reported vasculitis for vaccines). For the more specific terms, Henoch-Schoenlein Purpura (HSP) was most frequently reported, (19.1% on average), followed by Kawasaki disease (KD) (16.1% on average) and polymyalgia rheumatica (PMR) (9.2% on average). Less frequently reported subtypes were cutaneous vasculitis (CuV), vasculitis of the central nervous system (CNS-V), and Behcet's syndrome (BS). HSP, PMR and CuV were more frequently reported with influenza vaccines: on average in 29.3% for HSP reports, 61.5% for PMR reports and in 39.2% for CuV reports. KD was reported with pneumococcal vaccines in 32.0% of KD reports and with rotavirus vaccines in more than 20% of KD reports. BS was most frequently reported after hepatitis and HPV vaccines and CNS-V after HPV vaccines.

CONCLUSION

Similar reporting patterns of vasculitides were observed in different databases. Implementation of standardized case definitions for specific vasculitides could improve overall data quality and comparability of reports.

Vasculitis as an adverse event following immunization - Systematic literature review

BACKGROUND

Several types of vasculitis have been observed and reported in temporal association with the administration of various vaccines. A systematic review of current evidence is lacking.

OBJECTIVE

This systematic literature review aimed to assess available evidence and current reporting practice of vasculitides as adverse events following immunization (AEFI).

METHODS

We reviewed the literature from 1st January 1994 to 30th June 2014. This review comprises randomized controlled trials, observational studies, case series, case reports, reviews and comments regardless of vaccine and target population.

RESULTS

The initial search resulted in the identification of 6656 articles. Of these, 157 articles were assessed for eligibility and 75 studies were considered for analysis, including 6 retrospective/observational studies, 2 randomized controlled trials, 7 reviews, 11 case series, 46 case reports and 3 comments. Most of the larger, higher quality studies found no causal association between vaccination and subsequent development of vasculitis, including several studies on Kawasaki disease and Henoch-Schönlein purpura (IgA vasculitis). Smaller case series reported a few cases of vasculitis following BCG and vaccines against influenza and hepatitis. Only 24% of the articles reported using a case definition of vasculitis.

CONCLUSIONS

Existing literature does not allow establishing a causative link between vaccination and vasculitides. Further investigations were strengthened by the use of standardized case definitions and methods for data collection, analysis and presentation to improve data comparability and interpretation of vasculitis cases following immunization.

The first case of Kawasaki disease in a 20-month old baby following immunization with rotavirus vaccine and hepatitis A vaccine in China: A case report

Kawasaki disease (KD) after rotavirus and hepatitis A vaccination has not previously been reported in a baby in China. Herein, we describe a 20-month-old child who developed Kawasaki disease after receiving her second dose of Lanzhou lamb rotavirus vaccine (LLR) and her first dose of freeze-dried live attenuated hepatitis A vaccine. The case report was conducted by collecting and analyzing the hospital in-patient medical records and reviewing both the domestic and foreign pertinent literature. These findings will be important to note this possible side effect and to further investigate the association between the above 2 vaccines and Kawasaki disease.