Vaccine
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During a mass smallpox immunization campaign, vaccine may be exposed to ambient temperatures for extended periods of time. ⋯ After 2 weeks, viability was greater than 10(7)pfu/ml, the titer suggested by Frey et al. as necessary to ensure successful vaccination in more than 97% of vaccinees. When removed from refrigeration, keeping the vaccine on ice lowers the decline in titer.
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Vaccines are a key contributor to public health, especially in developing countries. Despite numerous demonstrations of the cost-effectiveness of immunisation, vaccines spending accounted for only 1.7% of the total pharmaceutical market in 2002, when UNICEF estimated that 34 million children were not reached by routine immunisation, most of them in developing countries. Several international organizations or initiatives, like the Global Alliance for Vaccines and Immunisation (GAVI), have defined a long-term goal of universal immunisation in developing countries. ⋯ Accounting for the main imponderables (such as delay in vaccines launch compared to industry plans) as well as probable phasing of vaccine introduction in countries, the total costs of immunisation would be reduced to US$ 14-17 billion over the same period. Vaccines-related costs represent the largest share (US$ 7.1-9.3 billion, among which 4.3-6.5 billion for new vaccines). This study advocates for the anticipation of the substantial financial resources needed to (a) purchase and introduce these vaccines in the developing countries in order to reduce the time lag between availability in industrialised and developing countries; and (b) stimulate vaccine researchers and manufacturers to continue research and development of much needed vaccines for the developing world.
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Randomized Controlled Trial Comparative Study Clinical Trial
Clinical experience with inactivated, virosomal influenza vaccine.
Current available influenza vaccines are safe and effective in preventing influenza. Nevertheless, there is a need for influenza vaccines with improved efficacy in the elderly. This need is underscored by both the observation that influenza has a major clinical and economic impact in the elderly and the fact that currently available vaccines are generally less effective in elderly than in younger subjects. ⋯ All three studies explored the long-term persistence of antibodies after vaccination with virosomal influenza vaccines. Immunogenicity declined over time but remained high at 4, 6 and 12 months post-vaccination compared to baseline, indicating that adequate seroprotection is achievable for the duration of the influenza season. Virosomal vaccines may induce better immunity in elderly subjects and may be more effective in reducing morbidity and mortality in this age group.
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Research efforts over the last two decades studying immune responses to human carcinomas have demonstrated that antigens expressed by tumor cells can elicit specific cellular and humoral immune responses. Unfortunately, despite the observation that existent immune responses to these antigens are present in some patients with cancer, the tumors continue to progress. ⋯ Some of the clinical trials of the first cancer vaccines have provided evidence of clinical benefit thus encouraging the development of other vaccines. Challenges to development of such cancer vaccines include the identification and characterization of the antigen(s) to be targeted, the definition of the desired immune response to be elicited by the vaccine, and the choice of the appropriate vaccine delivery system.
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Even though schistosomicidal agents and other control measures, including public hygiene and snail control exist, development of an efficacious vaccine still remains the most potentially powerful method for control of schistosomiasis. In our continuing efforts to develop a vaccine against schistosomiasis, we have selected a vaccine candidate (Sm-p80), which plays an important role in the immune evasion process of the parasite. Sm-p80 has been shown to confer up to 60% protection in mice following experimental infection. ⋯ No detectable IgG(3) or IgG(4) anti-Sm-p80 responses were present in the immunized baboons. The antibodies to Sm-p80 were able to kill up to 35% schistosomula in vitro in the presence of complement. These results although preliminary suggest the potential of Sm-p80 as a viable vaccine candidate for schistosomiasis.