What type of vaccine is the MMR vaccine?

The MMR vaccine, which protects against measles, mumps, and rubella, is classified as a live attenuated vaccine. This means it contains a weakened form of the virus that causes these diseases. The attenuation process reduces the virulence of the pathogens, allowing the immune system to recognize and respond to the vaccine without causing the diseases themselves.

Live attenuated vaccines are designed to mimic a natural infection closely, leading to robust immune responses, including the production of antibodies and long-lasting immunity. This allows the body to develop a memory of the pathogens, making it easier to fight off real infections in the future. The effectiveness of the MMR vaccine in building immune memory is one of the reasons it has been a critical component of childhood vaccination programs, significantly reducing the incidence of these serious diseases.