Seizures, encephalopathy, and vaccines: experience in the National Vaccine Injury Compensation Program

A review of China's compensation program for adverse reactions following immunization

Vaccination is a compelling measure to battle infectious diseases and protect public health. However, because of the constraints on human cognition, it is difficult to ensure that vaccines are safe. Adverse reactions to immunization can cause individual injury. In numerous countries, no-fault programs have been established to compensate individuals for vaccine-related injuries. China also established a vaccine injury compensation system with its own unique characteristics. The Vaccine Administration Law was promulgated in 2019 to establish a compensation system for those who experience adverse reactions following immunization; nevertheless, the compensation system is imperfect. Even when the applicable terms are applied to deal with vaccine-related injuries, some issues remain, such as unreasonable diagnosis and evaluation procedures for adverse reactions, excessively strict standards regarding proof and inconsistent compensation standards across the country. Therefore, to provide effective compensation for vaccine recipients, it is important to clarify the standards of proof and establish a sensible vaccine injury compensation system that includes Corona Virus Disease 2019 vaccine-injury compensation.

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.

[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.

Review of pediatric encephalitis and encephalopathy cases following immunization reported to the Canadian Immunization Monitoring Program Active (IMPACT) from 1992 to 2012

BACKGROUND

Neurological adverse events following immunization (AEFI) remain poorly characterized. Our objective was to describe pediatric acute and chronic encephalopathy and encephalitis cases following immunization reported via active sentinel surveillance from 1992 to 2012.

METHODS

This case series provides a descriptive analysis of encephalopathy/encephalitis admissions reported to the Canadian Immunization Monitoring Program ACTive (IMPACT). Acute cases were reported if symptom onset (seizures, decreased level of consciousness, change in mental status) occurred 0-7 days after tetanus or pertussis-containing vaccines, 0-15 days after other inactivated vaccines, or 5-30 days after live vaccines. Chronic cases of subacute sclerosing panencephalitis or subacute progressive rubella encephalitis were reported at any interval after vaccination. Clinical data were examined to identify possible causes for encephalopathy/encephalitis other than vaccination.

RESULTS

Sixty-one cases of encephalopathy/encephalitis following immunization were reported to IMPACT over 21 years; 57 (93.4%) were classified as acute and 4 (6.6%) were chronic cases of subacute sclerosing panencephalitis. Most patients (73.8%) were previously healthy and immunocompetent. The vaccines most frequently administered prior to presentation were diphtheria-tetanus-pertussis, measles-mumps-rubella, and influenza. At discharge, 38 patients (62.3%) had normal neurological status or were expected to recover. Forty patients (70.2%) with acute encephalopathy/encephalitis had a more likely alternate etiology besides vaccination based on neuroimaging, symptoms suggestive of infection, laboratory-confirmed non-vaccine-related infection, or clinical diagnosis. No cases of encephalitis were causally associated with pertussis or influenza vaccines. Two patients (50%) with subacute sclerosing panencephalitis had known wild-type measles infection prior to immunization. Three deaths were reported during hospitalization (4.9%); all were acute encephalitis/encephalopathy cases and none were confirmed to be vaccine-related.

CONCLUSIONS

Encephalopathy/encephalitis following immunization remains a rare but serious adverse event. Most cases had another more likely etiology than vaccination. Continued monitoring and analysis of AEFI is paramount to ensure the safety of immunization programs.

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

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

Economic and immunisation safety surveillance characteristics of countries implementing no-fault compensation programmes for vaccine injuries

Improvements in vaccine safety surveillance and investigative capacity lead to identification of rare reactions attributable to vaccination. As a result, the issue of fair compensation for those who experience vaccine injuries is gaining growing attention. Although vaccine injury compensation programmes (VICP) have been developed in a few countries for more than 50 years, no global policy guidance to guide vaccine injury compensation in all countries wishing to adopt such compensation schemes is currently available. To update the landscape analysis of no-fault compensation programmes and characterize VICP implementing countries, we conducted a survey of all 194 Member States from the World Health Organization and received feedback from 151. This analysis describes the economic and vaccine safety surveillance characteristics of Member States implementing VICPs. This analysis describes the characteristics of 25 Member States implementing a compensation programmes. Characteristics examined include economic, vaccination and safety surveillance indicators. Twenty of the 25 Member States (80%) with compensation programmes are categorized as high-income countries, 20/25 (80%) met the Global Vaccine Action Plan (GVAP) safety indicator of reporting at least ten annual reports of adverse events following immunization per 100,000 population, 21/25 (84%) met the GVAP coverage indicator by achieving greater than 90% third dose of Diphtheria, Tetanus and Pertussis vaccine (DTP3) and 17/25 (68%) assessed vaccine hesitancy in 2017. All Member States with VICP have a national immunization technical advisory group. This study identified growing interest in the implementation of no-fault compensation programs beyond high-income countries. Global policies guiding compensation should be developed for countries regardless of the maturity of their immunization programmes. RESEARCH IN CONTEXT: As a result of improved vaccine safety surveillance, World Health Organization (WHO) Member States are facing situations where known untoward serious vaccine reactions are documented, including in low- and middle-income settings. This has led to increased interest for the development of national no-fault compensation policies for vaccine injuries. As of 2010, compensation schemes for vaccine related injuries had been identified and characterized in 19 out of 194 WHO member states. All these programmes were in the industrialized world with none in low- and middle-income countries. Previous reviews have described the characteristics of the existing programmes based on the six common elements identified by Evans in 1999 with less emphasis on characteristics from countries implementing these no-fault compensation programmes. This manuscript aimed to identify predictors of countries implementing no-fault compensation programmes for vaccine injuries and update the inventory of existing programmes as part of a more comprehensive global landscape evaluation of existing programmes. This information will be useful for country self-evaluation and future compensation policy formulation as discussion to develop policies guiding the implementation of vaccine injury compensation continues to gain growing attention.

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.

Lactoferrin acts as an adjuvant during influenza vaccination of neonatal mice

Health policy precludes neonatal vaccination against influenza. Hence, morbidity and mortality are high under 6 months of age. Lactoferrin may activate diminished numbers of dysfunctional dendritic cells and reverse neonatal vaccine failures. Aluminum hydroxide/ALUM recruits neutrophils that secrete lactoferrin at deposition sites of antigen. We theorized lactoferrin + influenza antigen initiates an equivalent antibody response compared to ALUM. Three-day-old mice received subcutaneously 30 μg of H1N1 hemagglutinin + 200 μg of bovine lactoferrin versus hemagglutinin + ALUM. Controls received hemagglutinin, lactoferrin, or ALUM. After 21 days, sera measured anti-H1N1 (ELISA) and neutralizing antibody (plaque assays). ELISA detected equal antibody production with lactoferrin + hemagglutinin compared to hemagglutinin + ALUM; both sera also neutralized H1N1 virus at a 1:20 dilution (p < 0.01). Controls had no anti-H1N1 antibody. Neonates given lactoferrin had no anaphylaxis when challenged four weeks later. Lactoferrin is a safe and effective adjuvant for inducing antibody against influenza in neonates.