Hi there,

Instead of copying and pasting info from the Center for Disease Control website, I've included a helpful link below. Hopefully these answers address all of your questions.

Inactivated or "killed" vaccines: A chemical called formalin is used to kill the disease causing organism, but it still retain the antigen that triggers the body's immune response to create antibodies. Examples of this type of vaccine include the typhoid vaccine and the poliomyelitis vaccine.
Acellular vaccines: These vaccines use only the antigenic portion of the pathogen, such as its capsule, flagella, or protein cell wall. The Haemophilus influenzae B (HIB) vaccine is an example of an acellular vaccine. Since these vaccines don't produce a very strong immune response, they require a "booster" shot later on..
Attenuated vaccine: This type uses a weakened form or the live disease causing organism and creates the strongest immune response. Examples of attenuated vaccines include the one for measles, mumps, and rubella (MMR). Immunity lasts a lifetime.
Toxoid vaccine: The diphtheria and tetanus vaccines are examples of this type of immunization. They are made by using the toxin produced by the pathogen and then reducing its harmful affects with an aluminum salt. Toxoids require periodic booster shots.
Mimics: The vaccine for deadly smallpox was created this way by using the similar, but far less virulent, cowpox. In this instance, the immune response to the similar organism is enough to provide immunity.
Subunit vaccines: This recombinant DNA technology method of vaccine creation uses the genes of the pathogen that code for the parts of the organism that produce the strongest immune response. The genes are inserted into bacteria or yeast, which mass produce the desired proteins. These pathogenic but non-disease causing molecules can then be isolated, purified and used to produce the vaccine. The Hepatitis B vaccine is created this way.