The site Top Online Colleges has a quick, short, and to-the-point overview of the most important vaccines in human history:
10 Most Important Vaccines in Human History
If you like "info in a pill" on this topic, the site gives you a good start.
While we are talking "vaccines", there is a great article on the "Scientific American" portal about 6 Common Misconceptions about the Flu–and Flu Shots. Since the flu season is upon us, it's worth reading as a remainder to protect ourselves.