[Evaluation of the Brazilian surveillance system for adverse events following vaccination]. / Avaliação do sistema brasileiro de vigilância de eventos adversos pós-vacinação.

OBJECTIVES: To describe and evaluate the Brazilian system of passive surveillance of adverse events following immunization (PSAEFI). METHODS: The description and evaluation of PSAEFI were undertaken using the reported cases of adverse events following immunization with DTwP-Hib vaccine (AEFI-T), during the period from 2002 to 2005, using the Centers for Disease Control methodology. RESULTS: The PSAEFI system, which provides national coverage, is designed to standardize practices in cases of adverse events following immunization (AEFI) and to identify highly reactogenic lots of vaccine. The PSAEFI system proved its usefulness, simplicity and flexibility; despite low sensitivity, overestimate the proportion of sever events, but it consistently described AEFI-T, identifying fever, convulsions and hypotonic-hyporesponsive episodes as the most common events. It showed that 49.7% of AEFI-T occur after the first dose, and that 72.8% occur within the first six hours after vaccination. It facilitates public health decisions and epidemiological investigations. It is timely, 46.1% of all AEFI-T being reported within 10 days after vaccination and its completeness ranges from 70 to 90%, depending on the item evaluated. CONCLUSIONS: The PSAEFI system proved useful for monitoring DTwP-Hib vaccine safety. We recommended the incorporation of new methodologies, such the use of sentinel cities/hospitals and computerized immunization registries in order to increase its sensitivity.

Avaliação do sistema brasileiro de vigilância de eventos adversos pós-vacinação / Evaluation of the Brazilian surveillance system for adverse events following vaccination

OBJETIVOS: Descrever e avaliar o Sistema brasileiro de vigilância passiva de eventos adversos pós-vacinação (SPVEAPV). MÉTODOS: A descrição e avaliação do SPVEAPV fundamentaram-se nas notificações de eventos adversos pós-vacina Tetravalente ou DTwP/Hib - vacina adsorvida difteria, tétano, pertussis e Haemophilus influenzae b (conjugada) - (EAPV-T), durante o período de 2002 a 2005. Empregou-se a metodologia proposta pelo Centers for Disease Control and Prevention. RESULTADOS: O SPVEAPV apresenta abrangência nacional, tem por objetivos identificar e padronizar condutas frente a casos de eventos adversos pós-vacinação (EAPV) e identificar lotes reatogênicos. A vigilância é útil, simples e flexível, sua sensibilidade é baixa, superestima os eventos mais graves, mas descreve de forma consistente os EAPV-T, identificando a convulsão, a febre e o episódio hipotônico-hiporresponsivo como os mais frequentes, apontando a maior proporção de EAPV na primeira dose (49,7 por cento) e nas primeiras seis horas após a vacinação (72,8 por cento); é útil ao subsidiar decisões e investigações complementares; 46,1 por cento das notificações são feitas até 10 dias após a vacinação; sua completude varia de 70 por cento a 90 por cento, conforme o item. CONCLUSÕES: O SPVEAPV mostra-se útil no monitoramento da segurança da vacina DTwP/Hib, sendo, porém, recomendável a incorporação de novas metodologias como a de municípios e/ou hospitais sentinelas e a de sistemas informatizados de registros de imunização com a finalidade de elevar sua sensibilidade.

OBJECTIVES: To describe and evaluate the Brazilian system of passive surveillance of adverse events following immunization (PSAEFI). METHODS: The description and evaluation of PSAEFI were undertaken using the reported cases of adverse events following immunization with DTwP-Hib vaccine (AEFI-T), during the period from 2002 to 2005, using the Centers for Disease Control methodology. RESULTS: The PSAEFI system, which provides national coverage, is designed to standardize practices in cases of adverse events following immunization (AEFI) and to identify highly reactogenic lots of vaccine. The PSAEFI system proved its usefulness, simplicity and flexibility; despite low sensitivity, overestimate the proportion of sever events, but it consistently described AEFI-T, identifying fever, convulsions and hypotonic-hyporesponsive episodes as the most common events. It showed that 49.7 percent of AEFI-T occur after the first dose, and that 72.8 percent occur within the first six hours after vaccination. It facilitates public health decisions and epidemiological investigations. It is timely, 46.1 percent of all AEFI-T being reported within 10 days after vaccination and its completeness ranges from 70 to 90 percent, depending on the item evaluated. CONCLUSIONS: The PSAEFI system proved useful for monitoring DTwP-Hib vaccine safety. We recommended the incorporation of new methodologies, such the use of sentinel cities/hospitals and computerized immunization registries in order to increase its sensitivity.

Vigilância de eventos adversos pós-vacinação e segurança de programas de imunização: [revisão] / Vigilancia de eventos adversos post vacunación y seguridad de programas de inmunización: [revisión] / Surveillance of adverse effects following vaccination and safety of immunization programs: [review]

O objetivo da revisão foi analisar aspectos conceituais e operacionais de sistemas de vigilância de eventos adversos pós-vacina. Foram incluídos artigos disponíveis em formato eletrônico, publicados entre 1985 e 2009, selecionados nas bases Medline/PubMed, com as palavras-chave: "adverse events following vaccine", "adverse events following vaccine surveillance", "post-marketing surveillance" e "safety vaccine" e "Phase IV clinical trials", e excluídos aqueles com foco em tipos específicos desses eventos. Foram apontados os principais aspectos que justificam a importância dos eventos adversos pós-vacina em saúde pública, os instrumentos que garantem a segurança das vacinas e as finalidades, atributos, tipos, interpretações de dados, limitações e novos desafios da vigilância de eventos adversos pós-vacina, bem como estratégias para aumentar sua sensibilidade. A revisão é concluída com desafios para os próximos anos, visando à segurança e confiabilidade dos programas de vacinação.

El objetivo de la revisión fue analizar aspectos conceptuales y operacionales de sistemas de vigilancia de eventos adversos post vacuna. Fueron incluidos artículos disponibles en formato electrónico, publicados entre 1985 y 2009, seleccionados en las bases PubMed/Medline, con las palabras clave: "vigilancia de eventos adversos post vacuna", "vigilancia post comercialización", "seguridad de vacunas" y "estudios de Fase IV", y excluidos aquellos con foco en tipos específicos de tales eventos. Se señalaron los principales aspectos que justifican la importancia de los eventos adversos post vacuna en salud pública, los instrumentos que garantizan la seguridad de las vacunas y las finalidades, atributos, tipos, interpretaciones de datos, limitaciones y nuevos desafíos de la vigilancia de eventos adversos post vacuna, así como estrategias para aumentar su sensibilidad. Se concluye con desafíos para los próximos años, buscando seguridad y confiabilidad de los programas de vacunación.

Vigilância de eventos adversos pós-vacinação e segurança de programas de imunização / Surveillance of adverse effects following vaccination and safety of immunization programs

O objetivo da revisão foi analisar aspectos conceituais e operacionais de sistemas de vigilância de eventos adversos pós-vacina. Foram incluídos artigos disponíveis em formato eletrônico, publicados entre 1985 e 2009, selecionados nas bases Medline/PubMed, com as palavras-chave: "adverse events following vaccine", "adverse events following vaccine surveillance", "post-marketing surveillance" e "safety vaccine" e "Phase IV clinical trials", e excluídos aqueles com foco em tipos específicos desses eventos. Foram apontados os principais aspectos que justificam a importância dos eventos adversos pós-vacina em saúde pública, os instrumentos que garantem a segurança das vacinas e as finalidades, atributos, tipos, interpretações de dados, limitações e novos desafios da vigilância de eventos adversos pós-vacina, bem como estratégias para aumentar sua sensibilidade. A revisão é concluída com desafios para os próximos anos, visando à segurança e confiabilidade dos programas de vacinação.(AU)

Surveillance of adverse effects following vaccination and safety of immunization programs.

The aim of the review was to analyze conceptual and operational aspects of systems for surveillance of adverse events following immunization. Articles available in electronic format were included, published between 1985 and 2009, selected from the PubMed/Medline databases using the key words "adverse events following vaccine surveillance", "post-marketing surveillance", "safety vaccine" and "Phase IV clinical trials". Articles focusing on specific adverse events were excluded. The major aspects underlying the Public Health importance of adverse events following vaccination, the instruments aimed at ensuring vaccine safety, and the purpose, attributes, types, data interpretation issues, limitations, and further challenges in adverse events following immunization were describe, as well as strategies to improve sensitivity. The review was concluded by discussing the challenges to be faced in coming years with respect to ensuring the safety and reliability of vaccination programs.

Surveillance for adverse events after DTwP/Hib vaccination in Brazil: sensitivity and factors associated with reporting.

We estimated the sensitivity, i.e., the proportion of all cases of adverse events following immunization (AEFIs) reported to the Brazilian passive surveillance for adverse events following immunization (PSAEFI) with the diphtheria-tetanus-whole-cell pertussis-Haemophilus influenzae type b (DTwP/Hib) vaccine, as well as investigating factors associated with AEFIs reporting. During 2003-2004, 8303 AEFIs associated with DTwP-Hib were reported; hypotonic-hyporesponsive episodes (HHEs), fever and convulsions being the most common. Cure without sequel was achieved in 98.4% of the cases. The mean sensitivity of the PSAEFI was 22.3% and 31.6%, respectively, for HHE and convulsions, varying widely among states. Reporting rates correlated positively with the Human Development Index and coverage of adequate prenatal care, correlating negatively with infant mortality rates. Quality of life indicators and the degree of organization of health services are associated with greater PSAEFI sensitivity. In addition to consistently describing the principal AEFIs, PSAEFI showed the DTwP/Hib vaccine to be safe and allayed public fears related to its use.