The OECD validation study of the zebrafish embryo acute toxicity test (ZFET) for acute aquatic toxicity testing evaluated the ZFET reproducibility by testing 20 chemicals at 5 different concentrations in 3 independent runs in at least 3 laboratories. Stock solutions and test concentrations were analytically confirmed for 11 chemicals. Newly fertilised zebrafish eggs (20/concentration and control) were exposed for 96h to chemicals. Four apical endpoints were recorded daily as indicators of acute lethality: coagulation of the embryo, lack of somite formation, non-detachment of the tail bud from the yolk sac and lack of heartbeat. Results (LC50 values for 48/96h exposure) show that the ZFET is a robust method with a good intra- and inter-laboratory reproducibility (CV30%) for some very toxic or volatile chemicals, and chemicals tested close to their limit of solubility. The ZFET is now available as OECD Test Guideline 236. Considering the high predictive capacity of the ZFET demonstrated by Belanger et al. (2013) in their retrospective analysis of acute fish toxicity and fish embryo acute toxicity data, the ZFET is ready to be considered for acute fish toxicity for regulatory purposes.

This article summarizes the outcome of an international workshop organized by the European Partnership for Alternative Approaches to Animal Testing (EPAA) on Modern science for better quality control of medicinal products: Towards global harmonization of 3Rs in biologicals. As regards the safety testing of biologicals, the workshop participants agreed to actively encourage the deletion of abnormal toxicity tests and target animal batch safety tests from all relevant legal requirements and guidance documents (country-specific guidelines, pharmacopoeia monographs, WHO recommendations). To facilitate the global regulatory acceptance of non-animal methods for the potency testing of, e.g., human diphtheria and tetanus vaccines and veterinary swine erysipelas vaccines, international convergence on the scientific principles of the use of appropriately validated in vitro assays for replacing in vivo methods was identified as an overarching goal. The establishment of scientific requirements for new assays was recognized as a further means to unify regulatory approaches in different jurisdictions. It was recommended to include key regulators and manufacturers early in the corresponding discussions. Manufacturers and responsible expert groups, e.g. at the European Directorate for the Quality of Medicines and Health Care of the Council of Europe or the European Medicines Agency, were invited to consider leadership for international collaboration.

Within the Innovative Medicines Initiative 2 (IMI 2) project VAC2VAC (Vaccine batch to vaccine batch comparison by consistency testing), a workshop has been organised to discuss ways of improving the design of multi-centre validation studies and use the data generated for product-specific validation purposes. Moreover, aspects of validation within the consistency approach context were addressed. This report summarises the discussions and outlines the conclusions and recommendations agreed on by the workshop participants.