[Show abstract][Hide abstract] ABSTRACT: Routine influenza vaccination is currently recommended in several countries for people aged more than 60 or 65 years or with high risk of complications. A lower age threshold of 50 years has been recommended in the United States since 1999. To help policymakers consider whether such a policy should be adopted more widely, we conducted an economic evaluation of lowering the age limit for routine influenza vaccination to 50 years in Brazil, France, Germany, and Italy.
The probabilistic model was designed to compare in a single season the costs and clinical outcomes associated with two alternative vaccination policies for persons aged 50 to 64 years: reimbursement only for people at high risk of complications (current policy), and reimbursement for all individuals in this age group (proposed policy). Two perspectives were considered: third-party payer (TPP) and societal. Model inputs were obtained primarily from the published literature and validated through expert opinion. The historical distribution of annual influenza-like illness (ILI) incidence was used to simulate the uncertain incidence in any given season. We estimated gains in unadjusted and quality-adjusted life expectancy, and the cost per quality-adjusted life-year (QALY) gained. Deterministic and probabilistic sensitivity analyses were conducted.
Comparing the proposed to the current policy, the estimated mean costs per QALY gained were R$4,100, EURO 13,200, EURO 31,400 and EURO 15,700 for Brazil, France, Germany, and Italy, respectively, from a TPP perspective. From the societal perspective, the age-based policy is predicted to yield net cost savings in Germany and Italy, whereas the cost per QALY decreased to R$2800 for Brazil and EURO 8000 for France. The results were particularly sensitive to the ILI incidence rate, vaccine uptake, influenza fatality rate, and the costs of administering vaccination. Assuming a cost-effectiveness threshold ratio of EURO 50,000 per QALY gained, the probabilities of the new policy being cost-effective were 94% and 95% for France, 72% and near 100% for Germany, and 89% and 99% for Italy, from the TPP and societal perspectives, respectively.
Extending routine influenza vaccination to people more than 50 years of age is likely to be cost-effective in all four countries studied.
[Show abstract][Hide abstract] ABSTRACT: A influenza (gripe) é doença infecciosa aguda de origem viral que acomete o trato respiratório e a cada inverno atinge mais de 100 milhões de pessoas na Europa, Japão e Estados Unidos, causando anualmente a morte de cerca de 20 a 40 mil pessoas somente neste último país. O agente etiológico é o Myxovirus influenzae, ou vírus da gripe. Este subdivide-se nos tipos A, B e C, sendo que apenas os do tipo A e B apresentam relevância clínica em humanos. O vírus influenza apresenta altas taxas de mutação, o que resulta freqüentemente na inserção de novas variantes virais na comunidade, para as quais a população não apresenta imunidade. São poucas as opções disponíveis para o controle da influenza. Dentre essas, a vacinação constitui a forma mais eficaz para o controle da doença e de suas complicações. Em função das mutações que ocorrem naturalmente no vírus influenza, recomenda-se que a vacinação seja realizada anualmente. No Brasil, segundo dados obtidos pelo Projeto VigiGripe - ligado à Universidade Federal de São Paulo -, verifica-se que a influenza apresenta pico de atividade entre os meses de maio e setembro. Assim, a época mais indicada para a vacinação corresponde aos meses de março e abril. Para o tratamento específico da influenza estão disponíveis quatro medicamentos antivirais: os fármacos clássicos amantadina e rimantidina e os antivirais de segunda geração oseltamivir e zanamivir. Os últimos, acrescentam alternativas para o tratamento da influenza e ampliam as opções disponíveis para o seu controle.
No preview · Article · Apr 2003 · Revista da Sociedade Brasileira de Medicina Tropical
[Show abstract][Hide abstract] ABSTRACT: Influenza (flu) is an acute contagious viral infection characterized by inflammation of the respiratory tract that every winter affects more than 100 million people in Europe, Japan and the United States of America, also being responsible for several thousand of excess deaths (data from the United States reveal between 20,000 to 40,000 excess deaths annually). The Mixovirus influenzae is the agent that causes influenza, commonly called flu. There are 3 types of influenza virus: A, B, C, and only types A and B are perceived to be clinically relevant in humans. Due to the segmented nature of its genetic material, the influenza virus is highly mutagenic, causing frequent insertion of new antigenic strains into the community, against which the population presents no immunity. Presently, there are few options for the control of influenza and annual immunization is the most effective means to prevent disease and its complications. In Brazil, according to data collected by the VigiGripe's Project - linked to the Federal University of Sao Paulo -, circulation of the influenza virus also has a seasonal pattern, with peak activity occurring between May and September. Yearly vaccination is, therefore, best indicated on March and April. Currently, there are four medications available for the treatment of influenza viruses: amantadine and rimantadine, and two second generation pharmaceutical products, the neuraminidase inhibitors, oseltamivir and zanamivir. The latter two drugs have set the stage for a new approach to the management and control of influenza infections.
No preview · Article · Mar 2003 · Revista da Sociedade Brasileira de Medicina Tropical
[Show abstract][Hide abstract] ABSTRACT: Approximately 10% of the general population worldwide acquires influenza infection every year. Airline crews run a particularly high risk of contracting influenza and influenza-like viruses because they come in contact with hundreds of potentially infected individuals every day. Respiratory diseases are the most frequent cause of absenteeism among flight crews in airline companies. Several studies have shown the efficacy of influenza vaccination in the workplace of healthy, working adults leading to increased productivity and lower absenteeism. We conducted a double blind, randomized, placebo-controlled study on flight crews of an airline company in order to determine the safety and efficacy of a trivalent inactivated influenza vaccine in reducing illness and absences from work.
The 813 healthy members of a Brazilian airline company were randomly assigned to receive injections of either an influenza vaccine or a placebo, with a follow-up period of 7 mo after vaccination. Primary outcomes included influenza-like illness episodes and absenteeism from work due to such episodes.
Demographic characteristics were similar in the two groups. No significant side-effects occurred in either group. Compared to the placebo group, individuals receiving the vaccine showed 39.5% fewer episodes of flu-like illness (p < 0.001) and 26% fewer days of work lost (p = 0.03). The vaccinated group developed 33% fewer episodes of any severe flu-like illness (p < 0.01).
The data indicates that influenza vaccination is safe in airline flight crews and may produce health-related benefits including reduced absenteeism.
No preview · Article · Sep 2002 · Aviation Space and Environmental Medicine