The Study of Antiviral Compounds in Volunteers
This chapter is solely concerned with respiratory virus infections. Most of these are mild, self-limiting, and clinically ill-defined. It is perhaps fortunate that the infections which are the most difficult to assess under natural conditions are also ethically admissible for human experiments. Common colds, for example, generally have a sporadic incidence, are difficult to assign to particular infecting agents without laboratory help and much delay, and in addition cannot conveniently be studied in animal models. Hence the program of study of a potential antirhinovirus drug is conventionally that of laboratory experiment, toxicological and pharmacological testing in animals and man, and testing in volunteers who are deliberately infected with individual rhinoviruses. Influenza tends to differ somewhat in that it has a wide host range in many animals, some of which can be used in laboratory experiments (Chapter 1, Volume I), and also in the fact that it produces recognizable clinical patterns in man during the course of epidemics (Chapter 1). Nevertheless, there are wide differences in the virulence of influenza viruses for man and animals, 1 and the unpredictability of outbreaks in nature makes the standard epidemiological trial a very hazardous undertaking (Chapter 3).