Kikuchi-Fujimoto Disease and COVID-19 vaccination: pharmacovigilance approach.

Summary: Background. Kikuchi-Fujimoto Disease (KFD) or histiocytic necrotizing lymphadenitys is a rare disorder characterized by subacute necrotizing regional lymphadenopathy. It is usually presented as painful cervical nodes and associated with fever, headache, night sweats, nausea, vomiting and sore throat. Etiology of KFD is still unclear, two theories have been proposed: infections and autoimmune origin. Due to recent reports of KFD related to COVID-19 vaccination, the novelty of the mechanism of these vaccines and the immunomodulated role of both matters, a literature and adverse event databases review was carried out in order to shed light on the relationship between these two matters. Methods. A search in the Spanish and the European adverse events databases (FEDRA and Eudravigilance) was performed. Search criteria were any drug and the diagnosis "Histiocytic necrotizing lymphadenitis" according to the Medical Dictionary for Medical Activities version 25.0. All adverse events registered as June 2, 2022, were included. Results. FEDRA encompassed two KFD reports, one related to a mRNA COVID-19 vaccine. Eudravigilance included a total of 62 KFD cases, 14 of them associated to COVID-19 vaccines and eight to other vaccines. Conclusions. Pharmacovigilance is of utter importance in detecting adverse events caused by new vaccines. More research is needed to establish a final connection between KFD and COVD-19 vaccines, but due to the physiopathology of the condition, how vaccines stimulate the immune system and the high number of reported KFD cases with vaccines given its rare incidence, it is plausible to think that both entities are related.

[Vaccine-related adverse reactions in immunocompromised patients and in special situations of a hospital Vaccine Unit]. / Reacciones adversas asociadas a la vacunación en pacientes inmunodeprimidos y en situaciones especiales de una Unidad de Vacunas hospitalaria.

OBJECTIVE: The aim of the study was to describe the type of vaccines administered in the Vaccine Unit at a reference hospital. Calculate the overall and specific reporting rate of adverse reactions. METHODS: Retrospective observational study for the period between November 2014 and November 2017, on patients who developed an adverse drug reaction (ADR) after the administration of a vaccine and who were notified to the Spanish Pharmacovigilance System. The variables analyzed were age, sex, risk group, vaccine class, co-administration and type of ADR. A univariate and bivariate analysis was performed. The global and vaccine specific rate of ADR notification was calculated. RESULTS: A total of 18,123 vaccines were administered, of which 20.7% corresponded to hepatitis B virus vaccine. Fifty-three RAM suspects were reported. In 64.2% of cases only one vaccine was administered. Inactivated vaccines accounted for 88.7% of notifications. The highest number of notifications was generated by the 23 serotypes pneumococcal polysaccharide vaccine. The overall reporting rate was 0.42%. The hexavalent vaccine had the highest reporting rate (2.81%). 49.1% of the ADR were systemic. CONCLUSIONS: The overall reporting rate was low but higher than that of other authors. Proper reporting of possible adverse post-vaccine reactions is essential to contribute to vaccine safety and to increase public confidence in vaccines.

[Bronchospasm and flushing after vaccination with 23 serotype pneumococcal polysaccharide in chronic patients]. / Broncoespasmo y flushing tras la vacunación con neumococo polisacárida de 23 serotipos en pacientes crónicos.

OBJECTIVE: To describe the clinical-epidemiological characteristics of a series of suspected systemic adverse reactions registered with the 23 serotype pneumococcal polysaccharide vaccine (PNEUMOVAX23®). Calculate the cumulative incidence of the reaction and know if similar and/or compatible cases have been described in the scientific literature or in pharmacovigilance. METHODS: Observational and retrospective study realized between 01/12/2015 and 30/09/2017 in the Vaccines Unit of an autonomic reference hospital. We calculated the cumulative incidence of the adverse reaction for that vaccine. The common pharmacovigilance database (FEDRA) was consulted. RESULTS: Nine systemic adverse reactions were recorded (flushing + bronchospasm + SatO2<95%). The cumulative incidence was 1.036%. The outcome was recovered/resolved for everyone. No similar and/or compatible cases were found. CONCLUSIONS: The reactions described do not appear in the PNEUMOVAX23® data sheet. Epidemiologically, no causal relationship can be established between the symptoms and the variables studied. This study could be the basis for more detailed research that could modify the vaccine data sheet.