Large-scale field trials, application

A detailed description of plant virus vectors for expression of biopharmaceuticals is found in Chapter 4. The development of application of plant viral expression vectors for large-scale field trials involves many important issues. In order for production to be scaled up, it is necessary to have... 

Laboratory and outdoor tests have been combined with large-scale field trials. Because mulch films are exposed to a wide variety of conditions and the requirements change from region to region, the assessment of film lifetime is complex. The basic laboratory data can be used to define the appropriate additive system for specific needs. A complete set of information is needed relevant to the plastic article (type, polymer, thickness, pigment), the conditions of use (crop, way of application, expected lifetime and time to degradation) and the local environmental conditions. 

In this chapter, we have outlined the principal motives and methods that pertain to good pharma-covigilance. We have also tried to show how, in particular, risk-benefit analysis must always be on a case-by-case basis, and how it relies, ultimately, on the judgment of those experienced in this field rather than some automatically applicable arithmetic algorithm. Large-scale patient exposures will always trump clinical trials databases for rare types of adverse event, and this continues to be demonstrated by cases such as thalidomide, terfenadine and rofecoxib. 

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