Process of risk assessment by research ethics committees: foundations, shortcomings and open questions.

Risks and burdens in the study participation, as well as an adequate risk-benefit balance, are key concepts for the evaluation of clinical studies by research ethics committees (RECs). An adequate assessment and continuous monitoring to ensure compliance of risks and burdens in clinical trials have long been described as a central task in research ethics. However, there is currently no uniform and solid theoretical approach to risk assessment by RECs. Regulatory standards of research ethics such as the Declaration of Helsinki provide only minimal guidance on how risk decisions are considered. Due to discrepancies in the existing literature and guidance documents, adequate risk assessment by RECs remains to be elusive. In this article, we address current definitions of risk and present our own concept of aggregate risk definition. Moreover, we highlight the concept of benefit, the standard of reasonableness with respect to ethics literature and different approaches of risk-benefit assessment. In order to present a comprehensive theoretical approach of risk assessment by RECs, further understanding of the definitions of risk may improve adequate decision-making tasks by RECs. To improve the process of risk assessment by RECs, a dynamic framework will be illustrated, showing step-by-step risk assessment functions. This approach may be a promising tool to ensure adequacy in risk assessment by RECs.

Differences in lineage replacement dynamics of G1 and G2 rotavirus strains versus G9 strain over a period of 22 years in Bangladesh.

Group A rotaviruses (RVAs) have been a major cause of severe gastroenteritis in Bangladesh, mainly in children below the age of five. At the icddr,b, RVA strains collection and characterization dates back for more than 20 years. This sample collection was used to study the molecular evolution of the VP7 gene of G1, G2 and G9 RVA strains, which have been circulating in Bangladesh for most of this study period. The evolutionary rates (95% HPD) for G1, G2 and G9 were calculated to be 0.93×10(-3) (0.68-1.18), 1.45×10(-3) (1.12-1.78) and 1.07×10(-3) (0.78-1.39), respectively, which is in line with previous data for the RVA VP7 outer capsid protein, which is under strong negative selective pressure. Bayesian analyses revealed that for the G1 and G2 genotypes, one or multiple lineages co-circulated for one or a few seasons, frequently followed by replacement with genetically different lineages. This can be explained by the existence of a large variety of G1 and G2 RVA lineages and the rapid dissemination of different lineages across the globe. In contrast, circulating G9 lineages were rather closely related to each other across the study period and they were usually derived from variants circulating in the previous season(s). This is consistent with the fact that G9 RVAs have circulated in the human population for less than 20 years, and therefore their genetic diversity is much smaller, not resulting in the replacement of circulating G9 strains by highly divergent G9 lineages from abroad. Such different evolutionary dynamics for different RVA genotypes may alter their response to the selective pressure that might be exerted by the introduction of RVA vaccines and therefore a continued close monitoring is warranted.