ABSTRACT
One hundred years ago, at the turn of the century, was a Golden Era of microbiology and vaccination. The causative agents of many infectious diseases were identified as bacteria and vaccination to develop specific immunity in humans and animals was becoming popular (Golub and Green, 1991). Immunology, the science of immunity and immune systems, thus started with empirical practice. People then asked: How does it work? Knowledge of animal parasites greatly increased in medicine, veterinary medicine and zoology during the two hundred years from the middle of the 17th century to the 19th century (Hoeppli, 1959; Foster, 1965), well before the work of Pasteur, Koch and their schools established the role of bacteria in disease. It was appreciated by about the 1860's that parasites were responsible for many important diseases of humans and animals. Why did parasitology not give birth to immunology? Why has immunisation against major nematode infections of humans not been achieved? While hundreds of scientific papers about parasitic nematodes are published every year, and while nearly 70,000 tons of Ascaris eggs are being produced annually (if one applies Stall's estimate in 1947 to the present global epidemiological data (Stoll, 1947; Chan, 1997)), we are still unable to immunise humans against parasitic nematodes.
