Biologicals : journal of the International Association of Biological Standardization
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Three commonly used designs for vaccine safety assessment post licensure are cohort, case-control and self-controlled case series. These methods are often used with routine health databases and immunisation registries. This paper considers the issues that may arise when designing an epidemiological study, such as understanding the vaccine safety question, case definition and finding, limitations of data sources, uncontrolled confounding, and pitfalls that apply to the individual designs. The example of MMR and autism, where all three designs have been used, is presented to help consider these issues.
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Measurement of coagulation factor activity using absolute physico-chemical techniques is not possible and estimation therefore relies on comparative bioassay relative to a reference standard with a known or assigned potency. However the inherent variability of locally prepared and calibrated reference standards can give rise to poor agreement between laboratories and methods. Harmonisation of measurement between laboratories at the international level relies on the availability of a common source of calibration for local reference standards and this is provided by the World Health Organization (WHO) International Standards which define the International Unit for the analyte. This article describes the principles, practices and problems of biological standardisation and the development and use of reference standards for assays of coagulation factors, with particular emphasis on WHO International Standards for both concentrates and plasma.
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Injury is rapidly becoming the leading cause of death worldwide, and uncontrolled hemorrhage is the leading cause of potentially preventable death. In addition to crystalloid and/or colloid based resuscitation, severely injured trauma patients are routinely transfused RBCs, plasma, platelets, and in some centers either cryoprecipitate or fibrinogen concentrates or whole blood. Optimal timing and quantity of these products in the treatment of hypothermic, coagulopathic and acidotic trauma patients is unclear. ⋯ In fact data from the current war in Iraq and Afghanistan suggest otherwise. All of these factors have contributed to the current situation, whereby blood component therapy is highly variable and not driven by long term patient outcomes. This review will address the issues raised above and describe recent trauma patient outcome data utilizing predetermined plasma:platelet:RBC transfusion ratios and an ongoing prospective observational trauma transfusion study.
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Cell substrates are a key component of successful vaccine development and throughout the last several decades there has been a dramatic increase in the types of cells available for vaccine production. Nevertheless, there is a continued demand for new and innovative approaches for vaccine development and manufacturing. ⋯ Here we review vaccine antigen production in plant-based systems as was presented by Dr. Vidadi Yusibov of Fraunhofer USA Center for Molecular Biotechnology at the IABS International Scientific Workshop on NEW CELLS FOR NEW VACCINES II that was held in Wilmington, Delaware on September 17-19, 2007.
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Measles is one of the major causes of childhood mortality in developing countries, despite current prevention of over 2 million child deaths each year by measles vaccination programmes. New strategies, such as mass campaigns, and possibly new preparations of measles vaccines, may facilitate further progress in controlling the disease and improving the prospects for its ultimate eradication. To evaluate the potential for non-percutaneous routes of vaccine administration to improve control, we reviewed studies of serological responses to measles vaccine after intradermal, conjunctival, oral, aerosol and intranasal administration. ⋯ Thus, with the possible exception of very young infants, the aerosol route is promising and offers several theoretical and practical advantages as well. Further randomized trials should be conducted to evaluate comparative responses to aerosolized, intranasal, and subcutaneous vaccine, especially in those age ranges targeted for mass campaigns (most commonly 9 months to 15 years). The development of improved technology for aerosol delivery of measles vaccine would greatly advance the potential for wide scale use of this route, especially in mass campaigns in low income countries.