Vaccines are a group of pharmaceuticals that include some of the oldest biologically-made compounds. The Smallpox vaccine was introduced by Edward Jenner as early as in 1796 and Louis Pasteur created the first live attenuated bacterial (Chicken Cholera) and viral (Rabies) vaccines at the end of the 19th century.
A vaccine contains an antigen that is capable of inducing an immune response in a living organism and as such, typically enhances the organism’s ability to fight off or minimize disease. These antigens can be live attenuated (weakened) microorganisms such as in the MMR (Measles, Mumps, Rubella) virus vaccine, inactivated microbes (bacteria, virus) or parts thereof (proteins, polysaccharides) such as the DTaP (Diphtheria, Tetanus, acellular Pertussis) vaccine. More information on how typical vaccines are manufactured can be found here