This free, online text/course introduces the student to vaccinations. "The unit begins with the early history of smallpox – the first infectious disease to be eradicated by a vaccination programme. At the end of section 1," you will be asked to "read an article on the history of smallpox, then, before continuing further with this unit, you should turn to the case study on polio, where we discuss the prospects for making this the second infectious disease to be eradicated by vaccination. At the end of section 5 you will study the mini-lecture on vaccination. You will conclude your study of this chapter by conducting some internet research on the progress of vaccination programmes."