Vaccine development has now entered its fourth century. It is therefore, time to look back and consider the history of the field, which is now long and illustrious. In 1995, I organized a meeting in Paris that brought together a number of people who were intimately familiar with particular vaccines, and who in some cases were the actual developers of those vaccines, to talk about how those vaccines were developed. Their talks were transcribed and edited but never received wide dissemination. In this book, I have brought together those talks. Regrettably, many of the writers who recounted their personal achievements are now dead, but that makes these documents even more important.