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1.
PLoS Negl Trop Dis ; 13(7): e0007482, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31260441

RESUMO

The tetravalent dengue vaccine CYD-TDV (Dengvaxia) is the first licensed vaccine against dengue, but recent findings indicate an elevated risk of severe disease among vaccinees without prior dengue virus (DENV) exposure. The World Health Organization currently recommends CYD-TDV only for individuals with serological confirmation of past DENV exposure. Our objective was to evaluate the potential health impact and cost-effectiveness of vaccination following serological screening. To do so, we used an agent-based model to simulate DENV transmission with and without vaccination over a 10-year timeframe. Across a range of values for the proportion of vaccinees with prior DENV exposure, we projected the proportion of symptomatic and hospitalized cases averted as a function of the sensitivity and specificity of serological screening. Scenarios about the cost-effectiveness of screening and vaccination were chosen to be representative of Brazil and the Philippines. We found that public health impact depended primarily on sensitivity in high-transmission settings and on specificity in low-transmission settings. Cost-effectiveness could be achievable from the perspective of a public payer provided that sensitivity and the value of a disability-adjusted life-year were both high, but only in high-transmission settings. Requirements for reducing relative risk and achieving cost-effectiveness from an individual perspective were more restricted, due to the fact that those who test negative pay for screening but receive no benefit. Our results predict that cost-effectiveness could be achieved only in high-transmission areas of dengue-endemic countries with a relatively high per capita GDP, such as Panamá (13,680 USD), Brazil (8,649 USD), México (8,201 USD), or Thailand (5,807 USD). In conclusion, vaccination with CYD-TDV following serological screening could have a positive impact in some high-transmission settings, provided that screening is highly specific (to minimize individual harm), at least moderately sensitive (to maximize population benefit), and sufficiently inexpensive (depending on the setting).


Assuntos
Análise Custo-Benefício , Vacinas contra Dengue/economia , Dengue/prevenção & controle , Programas de Rastreamento/economia , Saúde Pública/economia , Vacinação/economia , Anticorpos Neutralizantes , Anticorpos Antivirais/sangue , Simulação por Computador , Dengue/economia , Humanos , Testes Sorológicos/economia , Fatores de Tempo , Vacinação/efeitos adversos , Cobertura Vacinal/estatística & dados numéricos , Organização Mundial da Saúde
2.
Value Health Reg Issues ; 18: 132-144, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31082793

RESUMO

OBJECTIVES: To review the literature on the cost-effectiveness of dengue vaccination in Southeast Asian countries and possibly to provide recommendations on promoting dengue vaccination in this region. METHODS: A systematic search was conducted to identify relevant articles in 3 major databases (ProQuest, American Society of Tropical Medicine and Hygiene, and PubMed). Complete economic evaluation studies, including willingness-to-pay (WTP) studies, that were conducted in any Southeast Asian country were included in this study. Systematic review, non-full-text, and non-English studies were specifically excluded. RESULTS: Nine selected studies highlighted the economic evaluation of dengue vaccination in Southeast Asian countries by considering many parameters (eg, vaccine cost, vaccine efficacy, cost-effectiveness threshold, economic assessment, public acceptance, and WTP). All studies confirmed that dengue vaccine can be used as a prevention strategy to reduce the incidence rate of dengue cases by providing a variance of high cost-effectiveness values. In addition, communities provided a good assessment, acceptance, and WTP value for the vaccine. CONCLUSIONS: The use of dengue vaccine could reduce the burden of disease and economic burden due to dengue infection in Southeast Asian countries. The efficacy of dengue vaccine was estimated to be 50-95% for those <9 years, 9 years, and >9 years. In particular, several studies reported that dengue vaccine could be categorized as a cost-effective intervention in Southeast Asian countries within certain conditions.


Assuntos
Vacinas contra Dengue/economia , Dengue/prevenção & controle , Ásia Sudeste , Análise Custo-Benefício , Dengue/economia , Dengue/epidemiologia , Humanos
3.
Pediatr Infect Dis J ; 37(11): 1184-1189, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30153226

RESUMO

BACKGROUND: Arboviruses including dengue (DENV), chikungunya (CHIKV) and Zika cause significant morbidity in Latin America. With multiple arbovirus vaccines in development, better understanding of community attitudes and acceptability for these vaccines is needed. METHODS: In September 2016, a cross-sectional survey assessed arbovirus knowledge, attitudes, vaccine demand and willingness-to-pay (WTP) at the conclusion of a DENV/norovirus surveillance study in rural Guatemala with high arbovirus endemicity. Factors associated with vaccine demand and WTP were assessed with regression analysis. RESULTS: Among 564 surveyed households, DENV knowledge was high. There was great concern for arboviruses, particularly CHIKV. Overall vaccine attitudes were positive with <5% identifying significant barriers, hesitancy or refusing previous vaccination. At 50% and 75% efficacy, 75% and 88% of respondents wanted arbovirus vaccines, respectively. DENV vaccine demand at 50% efficacy was associated with increased housing density, nonhealth postvaccination location, older children and medical source for information. For each vaccine, 52-55% of respondents were WTP $0-$3.40, while 16-17% were WTP ≥$6.81. WTP at $3.40 and $6.81 levels for all vaccines was associated positively with parental education but negatively with good DENV knowledge. History of purchasing and identifying barriers to vaccines was associated with WTP ≥$6.81. CONCLUSIONS: Demand for potential DENV, CHIKV and Zika vaccines is high at 50% and 75% efficacy in this Guatemalan community. Associated factors could be leveraged to optimize arbovirus vaccine implementation. Overall low WTP given current cost of Dengvaxia (Sanofi Pasteur, Lyon, France) suggests that government subsidization may be necessary in resource-poor regions, though a small private market may be supported.


Assuntos
Infecções por Arbovirus/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Vacinas Virais/economia , Adolescente , Adulto , Infecções por Arbovirus/economia , Arbovirus , Febre de Chikungunya/prevenção & controle , Criança , Pré-Escolar , Estudos Transversais , Vacinas contra Dengue/economia , Características da Família , Feminino , Guatemala , Humanos , Lactente , Masculino , Saúde Pública , População Rural/estatística & dados numéricos , Inquéritos e Questionários , Infecção por Zika virus/prevenção & controle
4.
Trans R Soc Trop Med Hyg ; 112(8): 369-377, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29982700

RESUMO

Background: After new analysis, Sanofi Pasteur now recommends their dengue vaccine (Dengvaxia) should only be given to individuals previously infected with dengue and the World Health Organization's recommendations regarding its use are currently being revised. As a result, the potential costs of performing large-scale individual dengue screening and/or dengue serosurveys have become an important consideration for decision making by policymakers in dengue-endemic areas. Methods: We used an ingredients-based approach to estimate the financial costs for conducting both a school-based dengue serosurvey and school-based individual dengue screening within a typical province in Vietnam, using an existing commercial indirect immunoglobulin G enzyme-linked immunosorbent assay kit. This costing is hypothetical and based on estimates regarding the resources that would be required to perform such activities. Results: We estimated that performing a school-based individual screening of 9-year-olds would cost US$9.25 per child tested or US$197,827 in total for a typical province. We also estimated that a school-based serosurvey would cost US$10,074, assuming one class from each of the grades that include 8- to 11-year-olds are sampled at each of the 12 selected schools across the province. Conclusions: The study indicates that using this vaccine safely on a large-scale will incur noteworthy operational costs. It is crucial that these be considered in future cost-effectiveness analyses informing how and where the vaccine is deployed.


Assuntos
Vacinas contra Dengue/economia , Vírus da Dengue/imunologia , Dengue/prevenção & controle , Programas de Imunização/economia , Programas de Rastreamento/economia , Serviços de Saúde Escolar/economia , Vacinação/economia , Criança , Análise Custo-Benefício , Custos e Análise de Custo , Assistência à Saúde/economia , Dengue/economia , Dengue/virologia , Vírus da Dengue/classificação , Ensaio de Imunoadsorção Enzimática/economia , Previsões , Humanos , Programas de Rastreamento/métodos , Seleção de Pacientes , Desenvolvimento de Programas/economia , Instituições Acadêmicas , Estudos Soroepidemiológicos , Sorogrupo , Vietnã , Organização Mundial da Saúde
5.
Vaccine ; 36(3): 413-420, 2018 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-29229427

RESUMO

Following publication of results from two phase-3 clinical trials in 10 countries or territories, endemic countries began licensing the first dengue vaccine in 2015. Using a published mathematical model, we evaluated the cost-effectiveness of dengue vaccination in populations similar to those at the trial sites in those same Latin American and Asian countries. Our main scenarios (30-year horizon, 80% coverage) entailed 3-dose routine vaccinations costing US$20/dose beginning at age 9, potentially supplemented by catch-up programs of 4- or 8-year cohorts. We obtained illness costs per case, dengue mortality, vaccine wastage, and vaccine administration costs from the literature. We estimated that routine vaccination would reduce yearly direct and indirect illness cost per capita by 22% (from US$10.51 to US$8.17) in the Latin American countries and by 23% (from US$5.78 to US$4.44) in the Asian countries. Using a health system perspective, the incremental cost-effectiveness ratio (ICER) averaged US$4,216/disability-adjusted life year (DALY) averted in the five Latin American countries (range: US$666/DALY in Puerto Rico to US$5,865/DALY in Mexico). In the five Asian countries, the ICER averaged US$3,751/DALY (range: US$1,935/DALY in Malaysia to US$5,101/DALY in the Philippines). From a health system perspective, the vaccine proved to be highly cost effective (ICER under one times the per capita GDP) in seven countries and cost effective (ICER 1-3 times the per capita GDP) in the remaining three countries. From a societal perspective, routine vaccination proved cost-saving in three countries. Including catch-up campaigns gave similar ICERs. Thus, this vaccine could have a favorable economic value in sites similar to those in the trials.


Assuntos
Análise Custo-Benefício , Vacinas contra Dengue/economia , Dengue/epidemiologia , Dengue/prevenção & controle , Doenças Endêmicas/prevenção & controle , Vacinação/economia , Adolescente , Ásia/epidemiologia , Criança , Vacinas contra Dengue/administração & dosagem , Humanos , América Latina/epidemiologia , Modelos Teóricos
6.
Hum Vaccin Immunother ; 13(11): 2612-2625, 2017 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-28933657

RESUMO

Dengue virus (DV) is the etiologic agent of dengue fever, the most significant mosquito-borne viral disease in humans. Most DV vaccine approaches are focused on generating antibody mediated responses; one such DV vaccine is approved for use in humans but its efficacy is limited. While it is clear that T cell responses play important role in DV infection and subsequent disease manifestations, fewer studies are aimed at developing vaccines that induce robust T cells responses. Potent T cell based vaccines require 2 critical components: the identification of specific T cell stimulating MHC associated peptides, and an optimized vaccine delivery vehicle capable of simultaneously delivering the antigens and any required adjuvants. We have previously identified and characterized DV specific HLA-A2 and -A24 binding DV serotypes conserved epitopes, and the feasibility of an epitope based vaccine for DV infection. In this study, we build on those previous studies and describe an investigational DV vaccine using T cell epitopes incorporated into a calcium phosphate nanoparticle (CaPNP) delivery system. This study presents a comprehensive analysis of functional immunogenicity of DV CaPNP/multipeptide formulations in vitro and in vivo and demonstrates the CaPNP/multipeptide vaccine is capable of inducing T cell responses against all 4 serotypes of DV. This synthetic vaccine is also cost effective, straightforward to manufacture, and stable at room temperature in a lyophilized form. This formulation may serve as an effective candidate DV vaccine that protects against all 4 serotypes as either a prophylactic or therapeutic vaccine.


Assuntos
Fosfatos de Cálcio/química , Vacinas contra Dengue/imunologia , Epitopos de Linfócito T/química , Imunização/métodos , Nanopartículas/administração & dosagem , Nanopartículas/química , Animais , Animais Geneticamente Modificados , Antígenos Virais/química , Antígenos Virais/imunologia , Fosfatos de Cálcio/administração & dosagem , Dengue/imunologia , Dengue/prevenção & controle , Dengue/terapia , Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/efeitos adversos , Vacinas contra Dengue/economia , Vírus da Dengue/química , Vírus da Dengue/imunologia , Sistemas de Liberação de Medicamentos , Epitopos de Linfócito T/imunologia , Antígeno HLA-A2/imunologia , Humanos , Imunogenicidade da Vacina , Camundongos , Linfócitos T/imunologia , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/efeitos adversos , Vacinas de Subunidades/economia , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/economia , Vacinas Sintéticas/imunologia
7.
PLoS Negl Trop Dis ; 11(8): e0005785, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28806786

RESUMO

INTRODUCTION: Dengue is a rapidly emerging vector-borne Neglected Tropical Disease, with a 30-fold increase in the number of cases reported since 1960. The economic cost of the illness is measured in the billions of dollars annually. Environmental change and unplanned urbanization are conspiring to raise the health and economic cost even further beyond the reach of health systems and households. The health-sector response has depended in large part on control of the Aedes aegypti and Ae. albopictus (mosquito) vectors. The cost-effectiveness of the first-ever dengue vaccine remains to be evaluated in the field. In this paper, we examine how it might affect the cost-effectiveness of sustained vector control. METHODS: We employ a dynamic Markov model of the effects of vector control on dengue in both vectors and humans over a 15-year period, in six countries: Brazil, Columbia, Malaysia, Mexico, the Philippines, and Thailand. We evaluate the cost (direct medical costs and control programme costs) and cost-effectiveness of sustained vector control, outbreak response and/or medical case management, in the presence of a (hypothetical) highly targeted and low cost immunization strategy using a (non-hypothetical) medium-efficacy vaccine. RESULTS: Sustained vector control using existing technologies would cost little more than outbreak response, given the associated costs of medical case management. If sustained use of existing or upcoming technologies (of similar price) reduce vector populations by 70-90%, the cost per disability-adjusted life year averted is 2013 US$ 679-1331 (best estimates) relative to no intervention. Sustained vector control could be highly cost-effective even with less effective technologies (50-70% reduction in vector populations) and in the presence of a highly targeted and low cost immunization strategy using a medium-efficacy vaccine. DISCUSSION: Economic evaluation of the first-ever dengue vaccine is ongoing. However, even under very optimistic assumptions about a highly targeted and low cost immunization strategy, our results suggest that sustained vector control will continue to play an important role in mitigating the impact of environmental change and urbanization on human health. If additional benefits for the control of other Aedes borne diseases, such as Chikungunya, yellow fever and Zika fever are taken into account, the investment case is even stronger. High-burden endemic countries should proceed to map populations to be covered by sustained vector control.


Assuntos
Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/economia , Dengue/economia , Dengue/prevenção & controle , Controle de Mosquitos/economia , Controle de Mosquitos/métodos , Aedes , Américas , Animais , Ásia , Doenças Transmissíveis Emergentes/economia , Doenças Transmissíveis Emergentes/prevenção & controle , Análise Custo-Benefício , Humanos , Mosquitos Vetores , Doenças Negligenciadas/economia , Doenças Negligenciadas/prevenção & controle
8.
Ann Clin Microbiol Antimicrob ; 16(1): 38, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28506229

RESUMO

BACKGROUND: The increasing burden associated with dengue in Latin America makes it essential to understand the community's interest in acquiring vaccines, as an input to plan its introduction in endemic regions. The objective of this study is to learn the felt demand for dengue vaccines by estimating the willingness to pay and its associated factors in endemic communities of the North Caribbean region of Colombia. METHODS: A population survey was administered from October to December 2015, including 1037 families in 11 municipalities in Colombia. One adult per family was interviewed on their perception and history of dengue. Participants received a description of four hypothetical scenarios of dengue vaccines, administered in a single dose or in 3 doses, with an effectiveness of 70% for 5 years or 95% for 30 years. The willingness to pay for each one of these vaccines was inquired vs. 5 hypothetical prices in Colombian pesos. RESULTS: Most participants recognized dengue as a serious disease in children (99.3%) and adults (98.6%). 33 (3.2%) of the total respondents reported having suffered dengue and 19 (57.6%) of them required hospitalization. The price of the vaccine was inversely related to the willingness to pay. In addition, single dose vaccines (compared to 3 doses) and one with a protection of 95% for 30 years (compared to an effectiveness of 70% for 5 years), were associated with greater willingness to pay. Greater willingness to pay was observed among the respondents who considered it likely to get the disease, either themselves (OR 1.56; CI 95% 1.08-2.26) or their children (OR 1.89; CI 95% 1.28-2.81), in the next 5 years. The participants who have been diagnosed with dengue also showed greater willingness to pay (OR 1.89; CI 95% 1.01-3.54) compared to those who did not have this history. CONCLUSION: Factors such as price, number of doses and effectiveness can independently influence the decision to purchase a vaccine against an endemic disease, such as dengue. Additionally, this study reveals that background and perceptions of the disease can affect individuals' interest in acquiring this type of preventive interventions.


Assuntos
Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/economia , Dengue/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Adulto , Região do Caribe/epidemiologia , Estudos de Coortes , Colômbia/epidemiologia , Dengue/diagnóstico , Dengue/economia , Dengue/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Participação do Paciente/economia , Participação do Paciente/psicologia , Fatores de Risco , Inquéritos e Questionários , Vacinação/economia , Vacinação/psicologia
9.
Am J Trop Med Hyg ; 96(5): 1227-1234, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28500811

RESUMO

AbstractThe first approved dengue vaccine, CYD-TDV, a chimeric, live-attenuated, tetravalent dengue virus vaccine, was recently licensed in 13 countries, including Brazil. In light of recent vaccine approval, we modeled the cost-effectiveness of potential vaccination policies mathematically based on data from recent vaccine efficacy trials that indicated that vaccine efficacy was lower in seronegative individuals than in seropositive individuals. In our analysis, we investigated several vaccination programs, including routine vaccination, with various vaccine coverage levels and those with and without large catch-up campaigns. As it is unclear whether the vaccine protects against infection or just against disease, our model incorporated both direct and indirect effects of vaccination. We found that in the presence of vaccine-induced indirect protection, the cost-effectiveness of dengue vaccination decreased with increasing vaccine coverage levels because the marginal returns of herd immunity decreases with vaccine coverage. All routine dengue vaccination programs that we considered were cost-effective, reducing dengue incidence significantly. Specifically, a routine dengue vaccination of 9-year-olds would be cost-effective when the cost of vaccination per individual is less than $262. Furthermore, the combination of routine vaccination and large catch-up campaigns resulted in a greater reduction of dengue burden (by up to 93%) than routine vaccination alone, making it a cost-effective intervention as long as the cost per course of vaccination is $255 or less. Our results show that dengue vaccination would be cost-effective in Brazil even with a relatively low vaccine efficacy in seronegative individuals.


Assuntos
Anticorpos Antivirais/sangue , Análise Custo-Benefício , Vacinas contra Dengue/economia , Dengue/prevenção & controle , Programas de Imunização/economia , Modelos Estatísticos , Vacinação/economia , Adolescente , Adulto , Brasil/epidemiologia , Criança , Dengue/epidemiologia , Dengue/imunologia , Dengue/virologia , Vacinas contra Dengue/administração & dosagem , Vírus da Dengue/imunologia , Feminino , Humanos , Soros Imunes/química , Imunidade Coletiva , Incidência , Masculino , Pessoa de Meia-Idade , Vacinas Atenuadas
10.
PLoS One ; 12(4): e0175020, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28380060

RESUMO

BACKGROUND: The incidence of dengue fever (DF) is steadily increasing in Mexico, burdening health systems with consequent morbidities and mortalities. On December 9th, 2015, Mexico became the first country for which the dengue vaccine was approved for use. In anticipation of a vaccine rollout, analysis of the cost-effectiveness of the dengue vaccination program that quantifies the dynamics of disease transmission is essential. METHODS: We developed a dynamic transmission model of dengue in Yucatán, Mexico and its proposed vaccination program to incorporate herd immunity into our analysis of cost-effectiveness analysis. Our model also incorporates important characteristics of dengue epidemiology, such as clinical cross-immunity and susceptibility enhancement upon secondary infection. Using our model, we evaluated the cost-effectiveness and economic impact of an imperfect dengue vaccine in Yucatán, Mexico. CONCLUSIONS: Our study indicates that a dengue vaccination program would prevent 90% of cases of symptomatic DF incidence as well as 90% of dengue hemorrhagic fever (DHF) incidence and dengue-related deaths annually. We conclude that a dengue vaccine program in Yucatán, Mexico would be very cost-effective as long as the vaccination cost per individual is less than $140 and $214 from health care and societal perspectives, respectively. Furthermore, at an exemplary vaccination cost of $250 USD per individual on average, dengue vaccination is likely to be cost-effective 43% and 88% of the time from health care and societal perspectives, respectively.


Assuntos
Vacinas contra Dengue/uso terapêutico , Dengue/prevenção & controle , Adolescente , Adulto , Criança , Análise Custo-Benefício , Dengue/economia , Dengue/epidemiologia , Dengue/transmissão , Vacinas contra Dengue/economia , Custos de Medicamentos/estatística & dados numéricos , Custos de Cuidados de Saúde/estatística & dados numéricos , Humanos , México/epidemiologia , Pessoa de Meia-Idade , Modelos Estatísticos , Adulto Jovem
11.
Pharmacoeconomics ; 35(5): 575-589, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28205150

RESUMO

BACKGROUND: Dengue disease poses a great economic burden in Malaysia. METHODS: This study evaluated the cost effectiveness and impact of dengue vaccination in Malaysia from both provider and societal perspectives using a dynamic transmission mathematical model. The model incorporated sensitivity analyses, Malaysia-specific data, evidence from recent phase III studies and pooled efficacy and long-term safety data to refine the estimates from previous published studies. Unit costs were valued in $US, year 2013 values. RESULTS: Six vaccination programmes employing a three-dose schedule were identified as the most likely programmes to be implemented. In all programmes, vaccination produced positive benefits expressed as reductions in dengue cases, dengue-related deaths, life-years lost, disability-adjusted life-years and dengue treatment costs. Instead of incremental cost-effectiveness ratios (ICERs), we evaluated the cost effectiveness of the programmes by calculating the threshold prices for a highly cost-effective strategy [ICER <1 × gross domestic product (GDP) per capita] and a cost-effective strategy (ICER between 1 and 3 × GDP per capita). We found that vaccination may be cost effective up to a price of $US32.39 for programme 6 (highly cost effective up to $US14.15) and up to a price of $US100.59 for programme 1 (highly cost effective up to $US47.96) from the provider perspective. The cost-effectiveness analysis is sensitive to under-reporting, vaccine protection duration and model time horizon. CONCLUSION: Routine vaccination for a population aged 13 years with a catch-up cohort aged 14-30 years in targeted hotspot areas appears to be the best-value strategy among those investigated. Dengue vaccination is a potentially good investment if the purchaser can negotiate a price at or below the cost-effective threshold price.


Assuntos
Efeitos Psicossociais da Doença , Vacinas contra Dengue/administração & dosagem , Dengue/prevenção & controle , Modelos Teóricos , Adolescente , Adulto , Análise Custo-Benefício , Dengue/economia , Vacinas contra Dengue/economia , Custos de Cuidados de Saúde , Humanos , Programas de Imunização/economia , Malásia , Vacinação/economia , Vacinação/métodos , Adulto Jovem
12.
Hum Vaccin Immunother ; 13(4): 786-790, 2017 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-27905832

RESUMO

The introduction of new vaccines is accompanied by a variety of challenges. Among these, very important ones concern the questions whether the public is willing to accept and willing to purchase the vaccine. Here we discuss factors associated with these questions in the context of vaccines that are becoming available against dengue virus infection. We reviewed published studies available from PubMed and Embase, conducting a meta-analysis when possible and narrative review when the data did not qualify for meta-analysis. We found that attitude toward vaccination and socioeconomic level had significant associations with dengue vaccine acceptance. In addition, socioeconomic level, knowledge, attitude and practice regarding dengue fever, having personally experienced dengue fever and vaccine price were associated with willingness to pay for dengue vaccine. To improve acceptance and willingness to pay for dengue vaccine, well-designed introduction programs that address the associated factors in a context-specific manner are essential.


Assuntos
Vacinas contra Dengue/economia , Vacinas contra Dengue/uso terapêutico , Aceitação pelo Paciente de Cuidados de Saúde , Vacinação/economia , Vacinação/psicologia , Dengue/prevenção & controle , Humanos
13.
Acta Trop ; 166: 249-256, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27908746

RESUMO

Vaccination strategies are being considered as a part of dengue prevention programs in endemic countries. To accelerate the introduction of dengue vaccine into the public sector program and private markets, understanding the private economic benefits of a dengue vaccine is therefore essential. The aim of this study was to assess the willingness to pay (WTP) for a dengue vaccine among community members in Indonesia and its associated explanatory variables. A community-based, cross-sectional survey was conducted in nine regencies of Aceh province, Indonesia, from November 2014 to March 2015. A pre-tested validated questionnaire was used to facilitate the interviews. To assess the explanatory variables influencing participants' WTP for a dengue vaccine, a linear regression analysis was employed. We interviewed 677 healthy community members; 476 participants (87.5% of the total) were included in the final analysis. An average individual was willing to pay around US-$ 4 (mean: US-$ 4.04; median: US-$ 3.97) for a dengue vaccine. Our final multivariate model revealed that working as a civil servant, living in the city, and having good knowledge on dengue viruses, a good attitude towards dengue, and good preventive practice against dengue virus infection were associated with a higher WTP (P<0.05). Our model suggests that marketing efforts should be directed to community members who are working in the suburbs especially as farmers. In addition, the results of our study underscore the need for low-cost quality vaccines, public sector subsidies for vaccinations, and intensifying efforts to further educate and encourage households regarding other dengue preventive measures, using trusted individuals as facilitators.


Assuntos
Vacinas contra Dengue/economia , Dengue/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Participação do Paciente/psicologia , Vacinação/psicologia , Adulto , Estudos Transversais , Dengue/prevenção & controle , Vírus da Dengue , Características da Família , Feminino , Voluntários Saudáveis , Humanos , Indonésia , Masculino , Pessoa de Meia-Idade , Motivação , Análise Multivariada , Participação do Paciente/economia , Inquéritos e Questionários , Vacinação/economia
14.
Vaccine ; 34(50): 6133-6147, 2016 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-27810313

RESUMO

BACKGROUND: Dengue fever is one of the most rapidly advancing viral vector-borne diseases worldwide and vaccine candidates are in the final stages of clinical trials, representing a decisive opportunity to control the disease. To decide whether and where to support the introduction of new vaccines it is crucial to assess costs imposed by the disease and cost-effectiveness of vaccine programmes. OBJECTIVE: To identify economic evidence about dengue fever immunization, by systematic review, to assist future policy decisions and investment. METHODS: The electronic search stage was conducted on PubMed/Medline, Embase, Web of Science, Global Health, NHS Economic Evaluation Database (NHS EED) and Latin American and Caribbean Health Sciences Literature (LILACS) databases. Searches were restricted to papers published between January 1970 and February 2016. Selected papers were quality assessed using three recognized checklists. RESULTS: Eleven relevant studies were identified and there is economic evidence of a satisfactory quality level, derived through modelling approaches, to conclude that dengue fever vaccines will be economically advantageous when compared to vector preventive strategies, despite uncertainties surrounding vaccine efficacy and costs per vaccine dose. Quality assessment based on checklists showed similar findings and although overall quality was considered satisfactory, there were relevant methodological issues not considered among studies reviewed. CONCLUSION: Several uncertainties still remain about effectiveness of dengue fever vaccines; however, the reviewed economic evidence suggests that, when available, the vaccine can be economically advantageous at moderate prices. Future research needs to confirm findings from the economic models by using actual costs and effectiveness data.


Assuntos
Análise Custo-Benefício , Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/economia , Dengue/economia , Dengue/prevenção & controle , Dengue/epidemiologia , Saúde Global , Humanos
15.
BMC Infect Dis ; 16(1): 705, 2016 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-27887591

RESUMO

BACKGROUND: Dengue is one of the most important vector-borne diseases in the world, causing significant morbidity and economic impact. In Colombia, dengue is a major public health problem. Departments of La Guajira, Cesar and Magdalena are dengue endemic areas. The objective of this research is to determine the seroprevalence and the incidence of dengue virus infection in the participating municipalities from these Departments, and also establish the association between individual and housing factors and vector indices with seroprevalence and incidence. We will also assess knowledge, attitudes and practices, and willingness-to-pay for dengue vaccine. METHODS: A cohort study will be assembled with a clustered multistage sampling in 11 endemic municipalities. Approximately 1000 homes will be visited to enroll people older than one year who living in these areas, who will be followed for 1 year. Dengue virus infections will be evaluated using IgG indirect ELISA and IgM and IgG capture ELISA. Additionally, vector indices will be measured, and adult mosquitoes will be captured with aspirators. Ovitraps will be used for continuous estimation of vector density. DISCUSSION: This research will generate necessary knowledge to design and implement strategies with a multidimensional approach that reduce dengue morbidity and mortality in La Guajira and other departments from Colombian Caribbean.


Assuntos
Vacinas contra Dengue/economia , Dengue/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Protocolos Clínicos , Colômbia/epidemiologia , Estudos Transversais , Dengue/diagnóstico , Dengue/economia , Dengue/prevenção & controle , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Necessidades e Demandas de Serviços de Saúde/economia , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Estudos Soroepidemiológicos , Adulto Jovem
16.
PLoS Med ; 13(11): e1002181, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27898668

RESUMO

BACKGROUND: Large Phase III trials across Asia and Latin America have recently demonstrated the efficacy of a recombinant, live-attenuated dengue vaccine (Dengvaxia) over the first 25 mo following vaccination. Subsequent data collected in the longer-term follow-up phase, however, have raised concerns about a potential increase in hospitalization risk of subsequent dengue infections, in particular among young, dengue-naïve vaccinees. We here report predictions from eight independent modelling groups on the long-term safety, public health impact, and cost-effectiveness of routine vaccination with Dengvaxia in a range of transmission settings, as characterised by seroprevalence levels among 9-y-olds (SP9). These predictions were conducted for the World Health Organization to inform their recommendations on optimal use of this vaccine. METHODS AND FINDINGS: The models adopted, with small variations, a parsimonious vaccine mode of action that was able to reproduce quantitative features of the observed trial data. The adopted mode of action assumed that vaccination, similarly to natural infection, induces transient, heterologous protection and, further, establishes a long-lasting immunogenic memory, which determines disease severity of subsequent infections. The default vaccination policy considered was routine vaccination of 9-y-old children in a three-dose schedule at 80% coverage. The outcomes examined were the impact of vaccination on infections, symptomatic dengue, hospitalised dengue, deaths, and cost-effectiveness over a 30-y postvaccination period. Case definitions were chosen in accordance with the Phase III trials. All models predicted that in settings with moderate to high dengue endemicity (SP9 ≥ 50%), the default vaccination policy would reduce the burden of dengue disease for the population by 6%-25% (all simulations: -3%-34%) and in high-transmission settings (SP9 ≥ 70%) by 13%-25% (all simulations: 10%- 34%). These endemicity levels are representative of the participating sites in both Phase III trials. In contrast, in settings with low transmission intensity (SP9 ≤ 30%), the models predicted that vaccination could lead to a substantial increase in hospitalisation because of dengue. Modelling reduced vaccine coverage or the addition of catch-up campaigns showed that the impact of vaccination scaled approximately linearly with the number of people vaccinated. In assessing the optimal age of vaccination, we found that targeting older children could increase the net benefit of vaccination in settings with moderate transmission intensity (SP9 = 50%). Overall, vaccination was predicted to be potentially cost-effective in most endemic settings if priced competitively. The results are based on the assumption that the vaccine acts similarly to natural infection. This assumption is consistent with the available trial results but cannot be directly validated in the absence of additional data. Furthermore, uncertainties remain regarding the level of protection provided against disease versus infection and the rate at which vaccine-induced protection declines. CONCLUSIONS: Dengvaxia has the potential to reduce the burden of dengue disease in areas of moderate to high dengue endemicity. However, the potential risks of vaccination in areas with limited exposure to dengue as well as the local costs and benefits of routine vaccination are important considerations for the inclusion of Dengvaxia into existing immunisation programmes. These results were important inputs into WHO global policy for use of this licensed dengue vaccine.


Assuntos
Vacinas contra Dengue/economia , Vacinas contra Dengue/normas , Modelos Teóricos , Saúde Pública , Segurança , Vacinação/métodos , Criança , Análise Custo-Benefício , Vacinas contra Dengue/efeitos adversos , Humanos , Estudos Soroepidemiológicos , Vacinação/efeitos adversos , Vacinação/economia , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/economia , Vacinas Atenuadas/normas , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/economia , Vacinas Sintéticas/normas
17.
Am J Trop Med Hyg ; 95(5): 1137-1147, 2016 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-27601519

RESUMO

Dengue is one of the most problematic vector-borne diseases in the Philippines, with an estimated 842,867 cases resulting in medical costs of $345 million U.S. dollars annually. In December 2015, the first dengue vaccine, known as chimeric yellow fever virus-dengue virus tetravalent dengue vaccine, was approved for use in the Philippines and is given to children 9 years of age. To estimate the cost-effectiveness of dengue vaccination in the Philippines, we developed an age-structured model of dengue transmission and vaccination. Using our model, we compared two vaccination scenarios entailing routine vaccination programs both with and without catch-up vaccination. Our results indicate that the higher the cost of vaccination, the less cost-effective the dengue vaccination program. With the current dengue vaccination program that vaccinates children 9 years of age, dengue vaccination is cost-effective for vaccination costs up to $70 from a health-care perspective and up to $75 from a societal perspective. Under a favorable scenario consisting of 1 year of catch-up vaccinations that target children 9-15 years of age, followed by regular vaccination of 9-year-old children, vaccination is cost-effective at costs up to $72 from a health-care perspective and up to $78 from a societal perspective. In general, dengue vaccination is expected to reduce the incidence of both dengue fever and dengue hemorrhagic fever /dengue shock syndrome. Our results demonstrate that even at relatively low vaccine efficacies, age-targeted vaccination may still be cost-effective provided the vaccination cost is sufficiently low.


Assuntos
Vacinas contra Dengue/economia , Dengue/epidemiologia , Programas de Imunização/economia , Dengue Grave/epidemiologia , Adolescente , Criança , Análise Custo-Benefício , Dengue/prevenção & controle , Vacinas contra Dengue/administração & dosagem , Vírus da Dengue , Humanos , Modelos Econômicos , Filipinas/epidemiologia , Dengue Grave/prevenção & controle , Vacinação/economia , Vírus da Febre Amarela
18.
Drugs ; 76(13): 1301-1312, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27506852

RESUMO

Tetravalent, live-attenuated, dengue vaccine (Dengvaxia(®); CYD-TDV) is the first vaccine approved for the prevention of dengue disease caused by dengue virus (DENV) serotypes 1-4 in individuals aged 9-45 or 9-60 years living in high dengue endemic areas. This narrative review discusses the immunogenicity, protective efficacy, reactogenicity and safety of CYD-TDV in the prevention of dengue disease. In Latin American and Asian phase 3 trials in children and adolescents (n > 30,000), the recommended three-dose CYD-TDV regimen was efficacious in preventing virologically-confirmed dengue (VCD) during the period from 28 days after the last dose (month 13) to month 25, meeting the primary endpoint criteria. Protective efficacy against VCD in the respective individual trials was 60.8 and 56.5 % (primary analysis). During the 25-month active surveillance phase, CYD-TDV also provided protective efficacy against VCD, severe dengue, any grade of dengue haemorrhagic fever and VCD-related hospitalization in children aged 9 years and older. CYD-TDV was generally well tolerated, with no safety concerns identified after up to 4 years' follow-up (i.e. from post dose 1) in ongoing long-term studies. Based on evidence from the dengue clinical trial program, the WHO SAGE recommended that countries with high dengue endemicity consider introducing CYD-TDV as part of an integrated disease prevention strategy to lower disease burden. Pharmacoeconomic considerations will be pivotal to implementing dengue vaccination prevention strategies in these countries. The availability of a dengue vaccine is considered essential if the 2012 WHO global strategy targets for reducing the burden of dengue disease by 2020 are to be attained. Hence, CYD-TDV represents a major advance for the prevention of dengue disease in high dengue endemic regions.


Assuntos
Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/imunologia , Dengue/prevenção & controle , Adolescente , Adulto , Ásia , Criança , Pré-Escolar , Vacinas contra Dengue/efeitos adversos , Vacinas contra Dengue/economia , Vírus da Dengue/imunologia , Feminino , Humanos , América Latina , Masculino , Pessoa de Meia-Idade , Gravidez , Vacinas Atenuadas , Adulto Jovem
19.
PLoS Negl Trop Dis ; 10(5): e0004661, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27227883

RESUMO

Dengue vaccines will soon provide a new tool for reducing dengue disease, but the effectiveness of widespread vaccination campaigns has not yet been determined. We developed an agent-based dengue model representing movement of and transmission dynamics among people and mosquitoes in Yucatán, Mexico, and simulated various vaccine scenarios to evaluate effectiveness under those conditions. This model includes detailed spatial representation of the Yucatán population, including the location and movement of 1.8 million people between 375,000 households and 100,000 workplaces and schools. Where possible, we designed the model to use data sources with international coverage, to simplify re-parameterization for other regions. The simulation and analysis integrate 35 years of mild and severe case data (including dengue serotype when available), results of a seroprevalence survey, satellite imagery, and climatological, census, and economic data. To fit model parameters that are not directly informed by available data, such as disease reporting rates and dengue transmission parameters, we developed a parameter estimation toolkit called AbcSmc, which we have made publicly available. After fitting the simulation model to dengue case data, we forecasted transmission and assessed the relative effectiveness of several vaccination strategies over a 20 year period. Vaccine efficacy is based on phase III trial results for the Sanofi-Pasteur vaccine, Dengvaxia. We consider routine vaccination of 2, 9, or 16 year-olds, with and without a one-time catch-up campaign to age 30. Because the durability of Dengvaxia is not yet established, we consider hypothetical vaccines that confer either durable or waning immunity, and we evaluate the use of booster doses to counter waning. We find that plausible vaccination scenarios with a durable vaccine reduce annual dengue incidence by as much as 80% within five years. However, if vaccine efficacy wanes after administration, we find that there can be years with larger epidemics than would occur without any vaccination, and that vaccine booster doses are necessary to prevent this outcome.


Assuntos
Vacinas contra Dengue , Dengue/epidemiologia , Dengue/prevenção & controle , Adolescente , Criança , Pré-Escolar , Simulação por Computador , Dengue/economia , Dengue/transmissão , Vacinas contra Dengue/administração & dosagem , Vacinas contra Dengue/economia , Vacinas contra Dengue/imunologia , Epidemias/prevenção & controle , Feminino , Previsões , Humanos , Programas de Imunização , Imunização Secundária , Incidência , Masculino , México/epidemiologia , Estudos Soroepidemiológicos , Vacinação/tendências
20.
Medicina (B Aires) ; 76(2): 98-102, 2016.
Artigo em Espanhol | MEDLINE | ID: mdl-27028058

RESUMO

Dengue outbreaks have occurred yearly in Argentina since 1998. A number of candidate vaccines have been tested in endemic countries. The most advanced one was licensed in three countries of Latin America for children over 9 years of age. In the present article the benefits and drawbacks of these vaccines as well as the challenges for the implementation of a vaccination strategy in Argentina are discussed. Furthermore, a risk stratification strategy with new criteria and a multidisciplinary vision is suggested as a possible path for the assessment of the pertinence of a vaccination program in areas showing the highest risk of dengue transmission and/or for people at the greatest risk of developing severe dengue. It is also suggested that the definition regarding the status of endemicity should take into account the local realities. Finally, this paper proposes a broad discussion on the evidences, the expected impact and instrumental aspects that would be involved in the incorporation of a dengue vaccine, marketed or in development, into the national immunization program, and especially which subpopulation should be targeted for the immunization strategy to be cost-effective.


Assuntos
Vacinas contra Dengue/uso terapêutico , Dengue/prevenção & controle , Programas de Imunização/métodos , Argentina/epidemiologia , Criança , Dengue/epidemiologia , Vacinas contra Dengue/economia , Avaliação do Impacto na Saúde/estatística & dados numéricos , Humanos , Incidência
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