Malaria vaccine development: progress and challenges.

A safe and effective malaria vaccine would contribute greatly to the control and prevention of the disease. Although a review of global activity in malaria vaccine development does reflect significant activity, progress has remained slow. This article discusses the current vaccine candidates, with emphasis on those in the clinic, and explains the numerous challenges to making and evaluating malaria vaccines, which have resulted in only a few approaches being adopted and repeatedly evaluated. Against a parasite with more than 5200 genes, the lack of definitive knowledge regarding the nature of protective immunity and absence of reliable surrogates of protection are among the key challenges to a rational evaluation and prioritization of candidate vaccines. Pursuing the current R&D strategies may not result in the availability of a vaccine with characteristics suitable to impact significantly on disease morbidity in developing countries. Therefore, it is critical that the main challenges to malaria vaccine development be unambiguously identified and collectively addressed.

Qualification and quantification of fish protein in prepared surimi crabstick.

Species identification and protein quantification in surimi crabstick were achieved using sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE). When the Lowry and Kjeldahl protein determination methods were compared, the former showed more consistent results. Densitometric scanning of the gels was used for quantification of total fish protein as well as total egg white protein. The lower molecular weight proteins, 30 kDa and lower, proved to be the most useful in fish species identification as well as egg white protein addition. Using a combination of the myosin heavy chain band and the species-specific myosin light chain (Alaska pollock: 22.5 kDa; Pacific whiting: 24.4 kDa) proved the most accurate in calculating fish protein content of the crabstick sample, while for those samples that contained egg white, quantification was accomplished from the densitometric analysis of the overlapping bands of actin (45 kDa) from fish and ovalbumin from egg white. Lysozyme (14.3 kDa) proved to be a unique protein band in determining the presence of egg white when the content of dried egg white was equal to or exceeded 0.5% of the total weight of the final crabstick.

Ethical considerations related to the provision of care and treatment in vaccine trials.

Ethical principles of beneficence and justice combined with international human rights norms and standards create certain obligations on researchers, sponsors and public health authorities. These include treatment provision for participants enrolled in clinical trials of vaccines, drugs and other new preventive and curative technologies and methods. However, these obligations are poorly defined in practical terms, inconsistently understood or inadequately applied. Vaccine clinical trial designs normally define standards of prevention applicable to the population where the trial is to take place. The present document addresses specifically the setting of standards applicable to care and treatment in vaccine trials. The lack of clear guidance on how to achieve the optimal synergy between the development of new health technologies, on the one hand, and the promotion and protection of ethical and human rights principles, on the other, is a barrier to the progress of health research and therefore to the advancement of public health. The World Health Organization and UNAIDS have engaged in a series of consultations in Africa, the Americas, Asia and Europe to reflect on how this aim could best be achieved. This document highlights the outcome of these consultations. It proposes a structured approach to consensual decision making in the context of the clinical trial of vaccines against such public health challenges as HIV and newly emerging or threatening epidemics. A structured approach involving investigators and sponsors in a consultative process with trial communities and other stakeholders in research will ensure that the needs and legitimate expectations of trial participants are appropriately met, obligations towards them are delivered and, as a result, ethical research is facilitated in the interest of public health.