A vaccine is a preparation used to prevent a specific infectious disease by inducing immunity in the host against a specific pathogenic microorganism. Beginning in the 1950s, with the discovery of antibiotics, interest in vaccine research faded; however, the development of biotechnology and modern immunology has created new opportunities for producing new antigens, and vaccine research has become a significant focus once again. Vaccines have been developed against poliomyelitis, diphtheria, tetanus, pertussis, measles, mumps, rubella, influenza virus,
Hemophilus influenzae
serotype b, hepatitis B, hepatitis A, varicella, pneumococcus, meningococcus, rotavirus, herpes zoster, and human papilloma virus, which are all in commercial use. Vaccines being developed include those against respiratory syncytial virus, parainfluenza, herpes simplex, malaria, gonorrhea, and the human immunodeficiency virus. Details of these vaccines and the methods for their preparation and testing are discussed. Also discussed are future technologies, the effects of genetic engineering, adjuvants, combination vaccines, and economic considerations.