Rabbits, chimps and other animals were needed for dark ritualistic purposes and human volunteers were not forthcoming, especially after several high-profile medical scandals.
The Cavalier Pharmaceutical Company hit on the brilliant idea of publishing a series of primary school science and maths books. They donated them along with a generous endowment to Scarfolk Education Board which had no choice but to introduce the books to the curriculum.
The textbooks invited young children to conduct experiments on themselves and record the data, which contributed to higher end-of-year grades. The best scoring pupils from each school were awarded the chance to try out the medicine to which their schoolwork had contributed. They also won free cigarettes, as well as courses of either anti-seizure or anti-psychotic medication.
There's another page from the Scarfolk maths and science book here.