Vaccines

Vaccines are among the most successful health interventions against infectious diseases currently available. They prevent infectious diseases and are relatively cheap, making them very cost-effective. The chapter starts with an introduction to vaccine immunology, discussing the function of the innate and adaptive immune system and the role of vaccine components (adjuvants and antigens) in activating them. An overview is given of the different arms of the adaptive immune response: humoral and cellular immunity and the concept of immunological memory. Vaccines are a heterogeneous product group, ranging from classical live attenuated pathogens to fully synthetic peptides. The different vaccine concepts are discussed. Pros and cons of each concept are discussed, and representative examples are given. Platform technology based on viral vectors and mRNA, so successfully deployed during the COVID-19 pandemic, is also discussed. The last part of the chapter is devoted to general aspects of vaccinology and vaccine development and manufacturing. This includes vaccine adjuvants, needle-free administration routes, vaccine production, and characterization. After studying this chapter, the reader will have a basic understanding of vaccine immunology and knows the different types of vaccines, including mRNA and vector vaccines, how they work, how adjuvants work, and how vaccines are produced and controlled.