An attenuated vaccine is a type of vaccine that is made from live, weakened viruses or bacteria. There are several synonyms for attenuated vaccine which include live attenuated vaccine or just live vaccine. Other synonyms include weakened vaccine or attenuated virus vaccine. Attenuated vaccines are an effective way to protect people against certain diseases because they stimulate the immune system to create a protective response without causing the disease. Examples of attenuated vaccines include the measles, mumps, and rubella (MMR) vaccine, the varicella (chickenpox) vaccine, and the yellow fever vaccine. These vaccines are important in preventing disease outbreaks and maintaining public health.