Basic Concepts of Vaccine Immunology

Any statistician working in clinical vaccine research must have a good understanding of how vaccines work. Therefore, in this introductionairy chapter the fundamentals of vaccination, the immune system and vaccines are presented. The principle of vaccination is explained, mimicking a natural infection to prime the immune system so that it can fight of quickly infectious organisms it has encountered before. The four major infectious microorganisms are introduced: bacteria, yeasts, protozoa and viruses. It is explained how these organisms replicate, and how they are cleared from the body. The primary defence mechanism of microorganisms – antigenic variation – is discussed. A sketch of the immune system is given so that the reader will understand roughly how it works, including the distinction between the innate and the adaptive immune system. The chapter proceeds with a short section on the basics of tumour immunology. An overview is given of the several types of vaccines for viruses and bacteria, from the first generation live-attenuated vaccines to third generation vaccines like recombinant vector vaccines, DNA vaccines and virus-like particles vaccines. As an example of a parasite vaccine, the state of affairs of malaria vaccine development are discussed. Therapeutic vaccines for noninfectious diseases, a recent development, are briefly touched upon.