Reações de hipersensibilidade a vacinas / Hypersensitivity reactions to vaccines

O desenvolvimento e a ampliação do uso das vacinas durante décadas contribuíram para o controle e erradicação de doenças infecciosas, causando um grande impacto na saúde pública no mundo. A análise de segurança das vacinas percorre criteriosos processos e fases dos estudos clínicos, um dos pilares essenciais para aprovação regulatória e utilização do produto na população. O evento supostamente atribuído à vacinação e imunização (ESAVI), terminologia atual, é definido como qualquer ocorrência médica indesejada após a vacinação que possui, ou não, uma relação causal com o uso de uma vacina ou outro imunobiológico. Cabe ressaltar que eventos adversos mais raros ou inesperados, incluindo os eventos de hipersensibilidade, poderão ocorrer na fase pós-comercialização, quando as vacinas são aplicadas em milhões de pessoas. Neste artigo, serão discutidos os principais aspectos relacionados aos eventos adversos de hipersensibilidade pós-vacinais de interesse do especialista, e os desafios frente ao reconhecimento do agente causal e conduta a ser adotada. Além disso, serão revisados os potenciais alérgenos presentes nas vacinas de uso rotineiro para auxiliar o profissional de saúde na identificação de pacientes com potencial de risco de ESAVI por tais componentes. A atualização do conhecimento acerca da segurança e dos benefícios das vacinas pelos profissionais de saúde, sobretudo em populações especiais, contribui para condutas em imunização mais apropriadas, reduzindo o risco de exposição a um possível alérgeno em pessoas comprovadamente alérgicas às vacinas ou a alguns dos seus componentes, além de evitar contraindicações desnecessárias em eventos coincidentes ou não graves.

The expansion of vaccine use and development in recent decades has contributed to the control and eradication of infectious diseases, causing a major impact on public health worldwide. Vaccine safety analysis, which involves careful processes and clinical study, is one of the essential pillars of regulatory approval and use in the population. In current terminology, events supposedly attributable to vaccination and immunization (ESAVI) are defined as any unwanted medical occurrence after vaccination that may or may not have a causal relationship with vaccines or other immunobiologicals. It is noteworthy that rare or unexpected adverse events, including hypersensitivity, can occur during the post-marketing phase, when vaccines are administered to millions of people. In this article, we will discuss the main aspects of post-vaccine hypersensitivity events of interest to specialists and challenges to recognizing the causal agent and appropriate clinical practice. Potential allergens in routine vaccines will also be reviewed to help health professionals identify patients with a potential risk of ESAVI due to such components. Updating health professionals' knowledge about the safety and benefits of vaccines, particularly in special populations, can contribute to more appropriate clinical practice regarding immunization, reducing the risk of exposure to possible allergens in people with allergies to vaccines or their components, avoiding unnecessary contraindications in coincidental or non-serious events.

Posicionamento da ASBAI sobre a vacinação de crianças de 5 a 11 anos contra a COVID-19 com a vacina Comirnaty/ Pfizer/BioNTech ­ 27/12/2021 / ASBAI's position on vaccination of children aged 5 to 11 years against COVID-19 with the Comirnaty/Pfizer/BioNTech vaccine ­ 12/27/2021

A Associação Brasileira de Alergia e Imunologia (ASBAI) se manifesta totalmente favorável à imunização contra a COVID-19 em indivíduos entre 5 e 11 anos, para a proteção não somente deste grupo, mas também de seus conviventes. A vacinação de crianças, demonstrada sua eficácia e segurança, é fundamental para o controle da circulação do vírus e proteção de indivíduos cuja resposta vacinal pode não ocorrer de modo eficiente, como os imunocomprometidos e idosos. A imunização de pessoas entre 5 e 11 anos deve ser uma estratégia de saúde pública fundamental para o controle da pandemia que nos assola desde março de 2020 com todas as suas graves consequências para a saúde pública e a economia.

The Brazilian Association of Allergy and Immunology (ASBAI) is totally in favor of immunization against COVID-19 in individuals between 5 and 11 years old, for the protection not only of this group, but also of their cohabitants. The vaccination of children, once its efficacy and safety has been demonstrated, is essential for controlling the circulation of the virus and protecting individuals whose vaccine response may not occur efficiently, such as the immunocompromised and the elderly. The immunization of people between the ages of 5 and 11 must be a fundamental public health strategy to control the pandemic that has been plaguing us since March 2020 with all its serious consequences for public health and the economy.

Safety of yellow fever vaccine administration in confirmed egg-allergic patients.

Yellow fever vaccine (YFV) is recommended in endemic areas but represents a risk for egg-allergic patients, as it is cultivated in embryonated eggs. This study aims to describe the outcomes of yellow fever vaccination in patients with confirmed egg allergy (EA). Methods:A prospective study was conducted from January 2018 to September 2019. EA was diagnosed through positive oral food challenge (OFC), recent history of anaphylaxis following egg contact (anaphylaxis in the last 6 months) or immediate allergic reaction in the last 2 months with positive specific IgE. A skinprick test (SPT) with YFV was performed. If the SPT was negative, an intradermal test (ID) was performed at a 1:100 dilution. If the ID was negative, a full dose of YFV was administered. If the skin prick test or ID were positive, the YFV was administered using a graded dosing protocol. Results: It was included 58 patients with confirmed egg allergy (36 M:22F), with a median age of 2.3 years (0.7-13.9 y/o). Forty-two patients had a positive OFC. Nine reported recent anaphylaxis. The other 7 had reactions in the last 2 months with positive specific IgE. During OFC, 15 presented anaphylaxis, while the other 27 presented hives and/or angioedema or vomiting. SPT with YFV was negative in all patients. ID was negative in 48 patients who uneventfully received a full dose of YFV. Ten patients had a positive ID and received YFV in graded doses. Six patients presented a mild reaction controlled with antihistamines, and 4 patients received the vaccine without reactions. Positive ID was significantly related to the vaccine reaction (p < 0.0001). Administration of YFV using a specific protocol was safe even in anaphylactic patients. However, we recommend performing the ID, which can help predict a higher risk of vaccine reaction. An appropriate setting is required to control adverse events.

Segurança da vacina de febre amarela em pacientes comprovadamente alérgicos à proteína do ovo / Safety of yellow fever vaccine in egg allergic patients

Introdução: A vacina de febre amarela, recomendada em áreas endêmicas, é contraindicada em alérgicos à proteína do ovo (APO) por ser cultivada em ovos de galinha embrionados. Objetivo: O objetivo do estudo foi mostrar a segurança da vacina de febre amarela em pacientes comprovadamente APO. Método: Foi realizado estudo prospectivo em hospital quaternário, no período de janeiro a outubro de 2018. Foram incluídos pacientes com APO confirmada por teste de provocação oral (TPO), reação anafilática à proteína do ovo nos últimos 6 meses, ou reação de APO nos últimos 2 meses associada à IgE específica positiva. Todos foram submetidos ao teste de puntura com a vacina na apresentação pura. Se negativo, realizado teste intradérmico (ID) com a vacina na diluição de 1:100. Se ID negativo, vacina aplicada em dose plena. Se teste de puntura ou ID positivo, vacina aplicada fracionada segundo protocolo de dessensibilização. Resultados: Dos 78 pacientes com história presumida de APO, confirmou-se o diagnóstico em 43 (30M:13F, mediana idade 2,7 a): 30 por TPO, 7 com anafilaxia em menos de 6 meses da vacina, e 6 com reação imediata após ingestão do ovo há menos de 2 meses e IgE específica positiva. Durante o TPO, 12 apresentaram anafilaxia, e os demais (18) apresentaram urticária e/ou angioedema ou vômitos. Todos os testes de puntura (43) foram negativos. ID foi negativo em 37 pacientes, que receberam a dose plena da vacina, sem reações. Apenas 6 apresentaram ID positivo e necessitaram dessensibilização para vacina. Metade desses pacientes (3/6) apresentou reações de hipersensibilidade leves e foi tratada com anti-H1 e/ou corticoide oral. O ID positivo foi significativamente relacionado à reação à vacina (p = 0,0016). Conclusão: Concluiuse ser possível vacinar alérgicos a ovo, com um protocolo seguro, mesmo em paciente comprovadamente anafilático. É necessária uma unidade especializada para sua realização, com capacidade de controlar possíveis situações de risco.

Introduction: The yellow fever vaccine (YFV) is recommended in endemic areas, but represents a risk for egg allergic (EA) patients, as it is cultivated in chicken embryos. Objective: This study aimed to describe the outcomes of YFV in patients with confirmed egg allergy. Methods: A prospective study was conducted in a quaternary hospital, from January to October 2018. EA was diagnosed through oral food challenge (OFC) or recent history of anaphylaxis following egg contact in the past 6 months or allergic reaction in the past 2 months with positive specific immunoglobulin E (IgE). Skin prick testing (SPT) with YFV was performed in all participants. If SPT was negative, an intradermal test (IDT) was performed at 1:100 dilution. If IDT was negative, a full dose of YFV was administered. If SPT was positive, the YFV was administered using a graded-dose protocol. Results: Among 78 patients with prior history of EA, 43 were confirmed (30 male to 13 female, median age of 2.7 years). Thirty patients had a positive OFC, seven reported recent anaphylaxis, and six had reactions in the past 2 months with positive specific IgE. During OFC, 12 patients had anaphylaxis and 18 had urticaria and/or angioedema or vomiting. SPT with YFV was negative in all patients (43). IDT was negative in 37 patients, who received a full dose of YFV, uneventfully. Six patients had a positive IDT and received the YFV in graded doses; half of them had a mild reaction controlled with antihistamines and three patients received the vaccine without reactions. Positive IDT was significantly related to vaccine reaction (p=0.0016). Conclusion: The YFV using a specific protocol was safe even in anaphylactic patients. An appropriate setting is required in order to control possible adverse events.

[Skin diseases in hemodialysis and kidney transplant patients]. / Alterações dermatológicas nos pacientes em hemodiálise e em transplantados.

Recently, the world is facing an escalate in the incidence of chronic kidney disease (CKD). Databases containing information about patients in end stage renal disease (ESRD), especially in the United States, were the sources of initial information about it. Brazil has the third largest population on dialysis in the world, and there are about 680 dialysis centers, spread across all units of the federation in the present, providing treatment to an estimated population of almost 90,000 patients. Cutaneous involvement in the chronic renal failure is characterized by a number of manifestations, which may be related to three processes: the primary renal disease, the uremic state, or the therapeutic measures used in their handling. The skin changes in these two classes of patients, dialysis and transplant recipients, have been the subject of several studies. n recent years, however, great progress has been achieved in these two therapeutic modalities, which may have changed not only the type of the dermatologic disorders associated with these two conditions, but also their intensity or frequency. This article aims to yield an update as to the topic skin diseases in hemodialysis and kidney transplant patients.

Alterações dermatológicas nos pacientes em hemodiálise e em transplantados / Skin diseases in hemodialysis and kidney transplant patients

Na atualidade, o mundo está enfrentando uma epidemia de doença renal crônica (DRC). Bases de dados contendo informações sobre os pacientes no estágio terminal da doença renal (DRCt), especialmente nos Estados Unidos, foram as fontes das primeiras informações a respeito deste assunto. O Brasil possui a terceira maior população em diálise no mundo, e atualmente existem cerca de 680 centros de diálise, distribuídos por todas as unidades da federação, atendendo uma população estimada em quase 90.000 pacientes. O envolvimento cutâneo na insuficiência renal crônica é caracterizado por uma diversidade de manifestações, as quais podem ser relacionadas a três processos: à doença renal primária; ao estado urêmico ou a medidas terapêuticas empregadas no seu manuseio. As alterações dermatológicas nessas duas classes de pacientes, dialisados e transplantados, já foram motivo de diversos estudos. Nos últimos anos, entretanto, grandes progressos foram alcançados nestas duas modalidades terapêuticas, os quais podem ter modificado tanto o tipo de alteração dermatológica associada a estas duas condições, quanto a sua intensidade ou frequência. Este artigo tem como objetivo oferecer uma atualização sobre o tema dermatoses em hemodialisados e transplantados.

Recently, the world is facing an escalate in the incidence of chronic kidney dis>ease (CKD). Databases containing information about patients in end stage renal disease (ESRD), especially in the United States, were the sources of initial information about it. Brazil has the third largest population on dialysis in the world, and there are about 680 dialysis centers, spread across all units of the federation in the present, providing treatment to an estimated population of almost 90,000 patients. Cutaneous involvement in the chronic renal failure is characterized by a number of manifestations, which may be related to three processes: the primary renal disease, the uremic state, or the therapeutic measures used in their handling. The skin changes in these two classes of patients, dialysis and transplant recipients, have been the subject of several studies. n recent years, however, great progress has been achieved in these two therapeutic modalities, which may have changed not only the type of the dermatologic disorders associated with these two conditions, but also their intensity or frequency. This article aims to yield an update as to the topic skin diseases in hemodialysis and kidney transplant patients.