EVERYDAY SCIENCE

Detailed explanation-1: -Live vaccines use a weakened (or attenuated) form of the germ that causes a disease. Because these vaccines are so similar to the natural infection that they help prevent, they create a strong and long-lasting immune response.

Detailed explanation-2: -Vaccines are made from microbes that are dead or inactive so that they are unable to cause disease. The antigen in the vaccine is the same as the antigen on the surface of the disease-causing microbe. The vaccine stimulates the body to produce antibodies against the antigen in the vaccine.

Detailed explanation-3: -In the process of making these vaccines, the toxins are weakened so they cannot cause illness. Weakened toxins are called toxoids. When the immune system receives a vaccine containing a toxoid, it learns how to fight off the natural toxin.

Detailed explanation-4: -The live, attenuated viral vaccines currently available and routinely recommended in the United States are MMR, varicella, rotavirus, and influenza (intranasal). Other non-routinely recommended live vaccines include adenovirus vaccine (used by the military), typhoid vaccine (Ty21a), and Bacille Calmette-Guerin (BCG).