We have been given a variety of vaccines in our childhood, such as the DPT vaccine, measles vaccine. As an adult, we also have to take the vaccine, for example, we take the flu vaccine every year. Even when you travel to Africa, taking some vaccines are recommended. You may have some doubts on vaccineyou will have: what is the vaccine; how do I decide to take vaccines; how will it help us in the future - some diseases such asAIDS and Alzheimer can be eliminated by the vaccine?