There are many different types of vaccines available and effective for different pathogens. Conducting your own research, describe the six main types of vaccines used and examples of diseases they are used to prevent. In addition, explain (briefly) the mechanisms of how each vaccine works and why they are effective for some infections and not for others. Also answer the question: Why do different diseases require different percentages of herd immunity? Respond in a 2-3 page double-spaced paper (Times New Roman, 12-point font) and use APA citation style to cite your references. The assignment is due by 11:59 PM EST on Sunday.