Name one of the two main types of vaccines.

Live attenuated vaccines are one of the two main types of vaccines because they are created using a weakened version of the pathogen that causes the disease. This weakening process allows the immune system to respond effectively to the vaccine without causing the full-blown illness. When someone receives a live attenuated vaccine, their body can produce a strong and lasting immune response, often resulting in long-term immunity against the disease.

The significance of live attenuated vaccines lies in their ability to mimic a natural infection, which helps to train the immune system to recognize and combat the actual pathogen if encountered in the future. This type of vaccine is commonly used for various diseases such as measles, mumps, rubella (MMR), and yellow fever, as they can generate robust immune reactions with fewer doses needed compared to some inactivated or subunit vaccines.