Attenuated Vaccine

An attenuated vaccine, or live attenuated vaccine, is a vaccine created by reducing the virulence of a pathogen while still keeping it viable, in contrast to an inactivated vaccine, which is produced by killing the pathogen entirely. Attenuated vaccines stimulate a strong and long-lasting immune response with a quicker onset than inactivated vaccines by encouraging the body to create antibodies and memory immune cells against the specific pathogen, but they are generally avoided during pregnancy and in patients with severe immunodeficiencies. Common examples of live attenuated vaccines include those for measles, mumps, rubella, yellow fever, varicella and some influenza vaccines.