1.3  Types of vaccines

Let’s now move on to look at the various types of vaccine. You might have been immunized by injection yourself, or seen children being given immunization by oral drops. What are the differences between these vaccines, and what do they contain?

Vaccines are made from weakened or killed bacteria or viruses, or extracts taken from them, which are intended to produce immunity against a disease. At present, there are no vaccines in the EPI in Ethiopia to prevent infections by fungi, protozoa, parasites or many other important bacterial and viral diseases — but researchers are trying to develop new vaccines, particularly against malaria and HIV. You will learn about the main antibacterial vaccines (which protect against bacterial infections) in Study Session 2 and the main antiviral vaccines (which protect against infections by viruses) in Study Session 3. Here we describe the five general types of vaccine and how they are made safe to use in the human body. They are:

• live-attenuated vaccines
• inactivated vaccines
• sub-unit vaccines
• recombinant vaccines
• conjugate vaccines.