Vaccine
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As part of the global poliovirus eradication strategy, oral poliovirus vaccine (OPV) has successfully contributed to reduce polio incidence rates globally. However, because of the OPV-related risks of vaccine associated paralytic poliomyelitis (VAPP) and vaccine-derived polioviruses (VDPVs) OPV cessation is required in order to achieve complete eradication of polio. ⋯ The ability of IPV to prevent poliovirus outbreaks and provide herd protection has been demonstrated in several circumstances and in various settings. This paper reviews clinical experiences with IPV administration and outcomes in various countries in Europe, the Americas, Africa and Asia.
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Pneumococcal conjugate vaccine use among young children has led to significant declines in invasive pneumococcal disease in the United States, but the impact on community-acquired pneumonia is unknown. We conducted population-based pneumonia surveillance among 794,282 Group Health members before and after infant vaccine introduction in 2000. We presumptively identified pneumonia episodes using diagnosis codes assigned to medical encounters and confirmed 17,513 outpatient and 6318 hospitalized events by reviewing chest radiograph reports or hospitalization records. There was evidence for a decline in rates of both outpatient and hospitalized pneumonia in children less than 1 year of age following vaccine introduction but there were no consistent reductions in pneumonia rates among older children and adults.
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Using population-based and epidemiologic data for 25 countries in Asia (22 GAVI-Alliance eligible countries, Thailand, China and Japan), a model-based approach was used to estimate averted cervical cancer cases and deaths, disability-adjusted life years (DALYs) and incremental cost-effectiveness ratios (I$/DALY averted) for vaccination of young adolescent girls against human papillomavirus (HPV) types 16 and 18. Absolute reduction in lifetime cancer risk varied between countries, depending on incidence, proportion attributable to HPV-16 and -18, and population age-structure; for example, with 70% coverage, cancer reduction was 57% in Indonesia, whereas in Cambodia, it was 49%. Screening of women over age 30 three times per lifetime, after vaccinating them as pre-adolescents, is expected to provide an additional 20% to 30% mortality reduction. ⋯ For the 22 GAVI Alliance-eligible countries, vaccinating 5 consecutive birth cohorts at 70% coverage would cost over US $500 million versus almost US $1.3 billion at per dose costs of $2 and $5, respectively. Including China and Thailand would add US $251 million to US $1.4 billion at per dose prices of $2 and $12.25, respectively. In the countries we assessed, vaccination of young adolescent girls against HPV-16 and -18 could be very cost-effective if the cost per vaccinated girl is less than I$10-I$25; for it to be affordable, however, even with financing assistance, vaccine prices may need to be even lower.
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Using population and epidemiologic data for 33 countries in Latin America and the Caribbean (LAC), a model-based approach estimated averted cervical cancer cases and deaths, disability-adjusted life years (DALYs) and incremental cost-effectiveness ratios (I$/DALY averted) for human papillomavirus (HPV) vaccination of young adolescent girls. Absolute reduction in lifetime cancer risk varied between countries, depending on incidence, proportion attributable to HPV-16 and 18, and population age-structure; for example, with 70% coverage, cancer reduction ranged from 40% in Mexico to more than 50% in Argentina. Screening of women over age 30 three times per lifetime, after vaccinating them as pre-adolescents, is expected to provide a relative increase of 25% to 30% in mortality reduction. ⋯ For the 33 countries, vaccinating 5 consecutive birth cohorts at 70% coverage would cost $360 million at $5.00 per dose, $811 million at $12.25 per dose, and $1.26 billion at $19.50 per dose. In the LAC region, if effective delivery mechanisms can achieve high coverage rates in young adolescent girls, vaccination against HPV-16 and 18 will provide similar health value for resources invested as other new vaccines such as rotavirus. If the cost per vaccinated girl is less than I$25 HPV-16/18 vaccination would be very cost-effective in all 33 countries; for it to be affordable, costs may need to be lower.
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We present the burden of human papillomavirus (HPV)-related cancers (cancers of the cervix, anogenital areas, and oral cavity and pharynx) in terms of incidence and mortality, for the countries of the Asia Pacific region. The region contains more than half of the world population, and manifests a wide geographic diversity in the prevalence of infection with HPV, and of incidence (and mortality) rates of cancer of the cervix. ⋯ The incidence of other anogenital cancers is low, especially in Asian populations; however, cancers of the mouth and pharynx show a wide range of rates, determined by exposures such as oral tobacco and alcohol and for cancer of the lip, ultraviolet radiation. We also present the estimates of the occurence of genital warts--largely caused by HPV 6 and 11--and the HPV type distribution in the spectrum of women with normal cytology, cervical lesions, and cervical cancer in the region.