Influenza: vaccination and treatment

Abstract

Few conditions exert such an enormous toll of absenteeism, suffering, medical consultations, hospitalization, death and economic loss as influenza. Patients at high risk of complications and mortality include the elderly and those with pre-existing cardiopulmonary disease.The outbreak in 1997 in Hong Kong, of avian H5N1 influenza in man, which resulted in six deaths among 18 hospitalized cases, and the recent isolation of H9N2 viruses from two children in Hong Kong, are reminders that preparation must be made for the next pandemic. Since the 1970s, efforts to control influenza have mostly focussed on the split product and surface antigen vaccines. These vaccines are of proven efficacy in healthy adults and are effective in elderly people with and without medical conditions putting them at high risk of complications and death following influenza infection.However, vaccine coverage is patchy and often low, and outbreaks of influenza are not uncommon in well-immunized residents of nursing homes. New vaccines and methods of vaccine delivery are being developed in attempts to overcome the limitations of existing vaccines.The antiviral drugs amantadine and rimantadine were developed in the 1960s, but have not been used widely due to their spectrum of activity, rapid emergence of resistance, and adverse effects associated with amantadine. The site of enzyme activity of the influenza neuraminidase is highly conserved between types, subtypes and strains of influenza and has emerged as the target of an exciting new class of antiviral agents that are effective both prophylactically and as therapy.

WHO guide on the economic evaluation of influenza vaccination

“…While the vaccine may match in any given year, over the longer term the match to the predominate strains will not always be successful 31. The vaccine match is important as it has been shown that a poor match will reduce the efficacy of the vaccine to prevent influenza illness 23, 24, 25.…”

Gripe aviar: lo que un intensivista debe conocer

“…Estos fármacos son eficaces frente al amplio espectro de la gripe A y de los virus B, e incluyen los 9 subtipos de la neuraminidasa en la especie aviar 91 .…”

“…La vacuna adaptada al frío, consistente en virus recombinantes, se entrega con una dosis más grande de partículas virales al tejido linfoide bronquial que la vacuna inactivada, dando por resultado una respuesta inmunológica más compleja y expandida 91 Técnica sensible Disponibilidad del virus para la identificación y su caracterización Resultados en 2-10 días La identificación por la inmunofluorescencia de los cultivos de célula o el análisis de la hemaglutinación-inhibición del cultivo de célula es requerido Prueba de la susceptibilidad del fármaco Puede ser utilizado para la producción y las pruebas de vacunas TABLA 5. Características principales de la prueba del cultivo del virus neuraminidasa, más los anticuerpos neutralizados y la respuesta secretora mucosa local de IgA mayor que la vacuna parenteral 91,101 , y una reducción de la cantidad y de la frecuencia del vertido viral en comparación con la vacuna inactivada tras la infección 34 .…”

“…Características principales de la prueba del cultivo del virus neuraminidasa, más los anticuerpos neutralizados y la respuesta secretora mucosa local de IgA mayor que la vacuna parenteral 91,101 , y una reducción de la cantidad y de la frecuencia del vertido viral en comparación con la vacuna inactivada tras la infección 34 .…”

Growth drivers and resistors of the influenza market: The importance of cell culture flu

“…4 For example, a recent study indicated that neuraminase mutations resulting in Tamiflu resistance were found in 18 per cent of patients. 5 There are two main types of flu vaccine: (i) TIVs (trivalent inactivated vaccines) composed of two A strains (H1N1 and H3N2) and one B virus (surface or split virion); 6 and (ii) LAIV (live attenuated vaccine). 7 The effectiveness of a vaccine depends on the age and immunocompetence of the vaccine recipient, together with the ability to match protection by the yearly vaccine with the most prevalent circulating viral strain.…”