Mathematical models provide unique insights to real-world problems. Within the context of infectious diseases, models are used to explore the dynamics of infections and control mechanisms. Human papillomavirus (HPV) globally infects about 630 million people, many of these infections develop into cancers and genital warts. Vaccines are available to protect against the most prevalent and devastating strains of HPV. The introduction of this vaccine as part of a national immunization program in Canada is a complex decision for policy-makers in which mathematical models can play a key role. We use the current recommendations provided by the World Health Organization to explore the integral role mathematical models have in the decision to incorporate the HPV vaccine within a national immunization program. We then provide a review of the literature discussing the role of mathematical models in the decision to include a vaccine in a national immunization program within the context of the HPV vaccine. Next, we evaluate the current standing of mathematical models used within the context of HPV immunization, to highlight the types of models used, underlying assumptions and general recommendations made about these immunization programs. Then, we create and analyze a model to explore the possibility of bettering the current HPV vaccine strategy in Canada. We focus on the effects of the grade of vaccination and the number of doses required to eradicate the targeted strains of HPV.

Mathematical models provide unique insights to real-world problems. Within the context of infectious diseases, models are used to explore the dynamics of infections and control mechanisms. Human papillomavirus (HPV) globally infects about 630 million people, many of these infections develop into cancers and genital warts. Vaccines are available to protect against the most prevalent and devastating strains of HPV. The introduction of this vaccine as part of a national immunization program in Canada is a complex decision for policy-makers in which mathematical models can play a key role. We use the current recommendations provided by the World Health Organization to explore the integral role mathematical models have in the decision to incorporate the HPV vaccine within a national immunization program. We then provide a review of the literature discussing the role of mathematical models in the decision to include a vaccine in a national immunization program within the context of the HPV vaccine. Next, we evaluate the current standing of mathematical models used within the context of HPV immunization, to highlight the types of models used, underlying assumptions and general recommendations made about these immunization programs. Then, we create and analyze a model to explore the possibility of bettering the current HPV vaccine strategy in Canada. We focus on the effects of the grade of vaccination and the number of doses required to eradicate the targeted strains of HPV.

La vaccination figure parmi les interventions sanitaires les plus efficaces et les plus rentables connues. Pourtant, des inégalités de couverture persistent entre les régions et les pays. Les interventions visant à améliorer la couverture vaccinale sont généralement regroupées soit comme interventions pour améliorer l’offre ou la prestation des services de santé, soit comme interventions pour stimuler la demande pour les services de vaccination. L’objectif de cette étude est d’évaluer si les interventions du côté de la demande qui visent à améliorer la couverture vaccinale peuvent accroître la vaccination de routine des enfants dans les pays en développement. Nous avons effectué une revue systématique et une méta-analyse des essais randomisés contrôlés ainsi que d’autres types d’études scientifiques réalisées dans des pays en développement. La population ciblée comprenait les parents et les gardiens d'enfants de moins de deux ans qui sont exposés à une intervention visant à accroître la demande de vaccination de routine des enfants. La recherche des études originales dans les différentes bases de données a été limitée aux études publiées avant septembre 2013 (dernière mise à jour le 25 Mars 2014) dans 6 langues. Onze études ont été sélectionnées puis classifiées dans deux catégories: (a) éducation ou transfert de connaissances (7 études) et (b) incitations (4 études). Les résultats de la métaanalyse ont démontré un impact positif des interventions sur la demande de vaccination des enfants dans les pays en développement (RR 1.30; 95% CI 1.17, 1.44). Ces impacts positifs ont été constatés autant pour les interventions qui comprennent l’éducation ou transfert de connaissances (RR 1.40; 95% CI1.20, 1.63) que pour les interventions de type incitation (RR 1.28; 95% CI 1.12, 1.45). Les résultats suggèrent que diverses stratégies visant à accroître la demande peuvent conduire à une augmentation de la couverture vaccinale dans différents pays en développement. / Vaccination is one of the most cost effective health interventions known. However, inequalities of the vaccination coverage persist between regions and countries. The interventions to improve the vaccination coverage are usually grouped either as interventions to improve the supply or the delivery of health services, or as interventions to stimulate the demand for immunization services. The objective of this study is to evaluate whether demand-side interventions can increase routine immunization of children in developing countries. We conducted a systematic review and a meta-analysis of randomized controlled trials and other types of scientific studies conducted in developing countries. The targeted population consisted of parents and guardians of children under two years of age which are exposed to an intervention designed to increase demand for routine immunization of children. Research studies in different databases were restricted to primary studies published before September 2013 (last update on March 25th, 2014) in 6 languages. Eleven studies were selected and classified into two categories: (1) education and knowledge transfer (7 studies) and (2) incentives (4 studies). The results of the meta-analysis demonstrated a positive impact of demand-side intervention for vaccination of children in developing countries (RR 1.30, 95% CI 1.17, 1.44). These positive impacts were found as well in the interventions that include education and knowledge transfer (RR 1.40, 95% CI1.20, 1.63) that in the interventions using incentives (RR 1.28, 95% CI 1.12, 1.45). The results suggest that strategies to increase demand are effective in improving uptake of childhood vaccines in developing countries.

Made available in DSpace on 2011-05-04T12:36:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2010 / Hoje em dia, uma série de vacinas são capazes de proteger as pessoas, reduzindo drasticamente a incidência de doenças. Para gerenciar as ações de imunização em saúde pública, o Programa Nacional de Imunizações foi criado em 1973. Através dos seus mecanismos de trabalho, tais como, fornecimento de vacinas para toda a população, financiada pelo Governo Federal, sem custos diretos para os vacinados; armazenamento, transporte e suprimento de vacinas em redes de frio adequadas; sistemas de informações confiáveis, o Programa Nacional de Imunizações tem êxito em seus objetivos por controlar várias doenças evitáveis pela imunização. No entanto, sabemos que a ocorrência de eventos adversos pode surgir após a administração desses produtos imunizantes EAPV. Para monitorar e controlar EAPV, a Vigilância Epidemiológica de Eventos Adversos Pós-Vacinação foi criado pelo Programa Nacional de Imunização, em 1992. Este serviço foi estruturado para reconhecer e identificar os casos de EAPV, subsidiar pesquisas, e assessorar os profissionais de saúde na vigilância de casos, entre outros objetivos que contribuem para o controle de vacinas, saúde e bem-estar da população. Para fazer o controle de eventos adversos, a Vigilância Epidemiológica de EAPV usa um formulário de notificação, manual de monitoramento com informações e instruções para notificar e investigar casos de EAPV e fornecer dados para o sistema de informação. Este último é fundamental para acompanhar os casos suspeitos e confirmados de EAPV, identificando os casos graves, os surtos e controlar os lotes de vacinas que podem causar eventos adversos à população vacinada. Desde 1998, o Programa Nacional de Imunizações tem administrado o Sistema de Informações de Eventos Adversos Pós-Vacinação, desenvolvido pela equipe técnica do Departamento de Informática do Ministério da Saúde DATASUS. Com base nas diretrizes e critérios para avaliação de sistemas de vigilância do Centers for Disease Control and Prevention (CDC) - Atlanta / EUA, várias falhas e erros foram apontadas no sistema, onde surgiu a proposta de um novo sistema de informação para melhorar a eficácia da Vigilância Epidemiológica de Eventos Adversos Pós-Vacinação. O sistema foi revisto de acordo com a padronização da Terminologia de Reações Adversas (WHO-ART) e o Dicionário Médico de Atividades Reguladoras (MedDRA) da Rede Uppsala Monitoring Centre(UMC). O novo sistema de informações proposto nesta dissertação pode beneficiar de Vigilância Epidemiológica de Eventos Adversos Pós-Vacinação facilitando o fluxo de dados de EAPV, ampliando o acesso às informações aos diversos profissionais de saúdee fabricantes de vacinas, atualizando e facilitando a operação, enquanto mantém a segurança e privacidade da informação. Esta proposta inclui um novo formulário de notificação com base no atual formato em uso nas unidades de saúde no país, além das fichas de notificação dos sistemas de vigilância do Canadá e EUA. O Centro de Vigilância Epidemiológica da Secretária de Estado da Saúde de São Paulo, também contribuiu com o seu modelo de formulário. / Nowadays, a number of vaccines are able to protect people, reducing dramatically the incidence of diseases. To manage the immunizing actions in public health, the Brazilian National Immunization Program was created in 1973. Through its working mechanisms, such as, providing vaccines for the whole population, funded the Federal Government, without direct cost for vaccinees; storage, transportation and supply of vaccines in appropriate cold chain settings; reliable information systems, the National Immunization Program has succeed in its goal to control many diseases preventable by immunization. However, we know that the occurrence of adverse events may follow the administration of immunizing products – AEFI. To monitor and control AEFI, the Epidemiological Surveillance of Adverse Events Following Immunization was created by National Immunization Program in 1992. This service was structured to recognize and identify AEFI cases, subsidize research work, and support health professionals in surveillance, and other objectives that contribute to vaccines control, health and welfare of the population. To control adverse events, AEFI’s Epidemiological Surveillance use a notification form, monitoring manual with information and instructions to report and investigate AEFI’s cases and supply data to the information system. The latter is critical to follow up suspected and confirmed cases of AEFI, identifying severe cases, outbreaks and monitor vaccine lots that may cause adverse events to the vaccinated population. Since 1998, the National Immunization Program has managed the Adverse Events Following Immunization’s Informations System, developed by the technical staff in the Ministry of Health Department - DATASUS. Based on the guidelines and criteria for evaluation of the Surveillance Systems for the Centers for Disease Control and Prevention (CDC) – Atlanta / USA, several flaws and errors in systems were pointed out, and a proposal for a new information system was conceived to improve the effectiveness of the Epidemiological Surveillance of Adverse Events Following Immunization. The system was revised according to the standardization of Adverse Reactions Terminology (WHO-ART) and Medical Dictionary of Regulatory Activities (MedDRA) of the Network Uppsala Monitoring Center (UMC). The new informations system proposed in this dissertation may benefit the Epidemiological Surveillance of Adverse Events Following Immunization by expediting the flow of AEFI’s data, expanding the access to information to various health professionals, and to vaccine manufacturers, updating and facilitating operation, while mantaining security and privacy. This proposal include a new notification form based on the current format in use in the health units in the country besides the notification forms of Surveillance Systems in Canada and USA. The Epidemiological Surveillance Center of State Secretary for Health in São Paulo, also contributed to its model of form.

This project examines the role of immunization registries and their effect on a health care delivery system. Recent efforts to attain coverage of child populations by recommended vaccines have included initiatives by federal and state agencies, as well as private foundations, to develop and implement statewide community-based childhood immunization registries.