VACCINES CAN BE LIVING OR DEAD

Living, weakened vaccine:

The vaccine contains virus or bacteria that are alive, but weakened due to having been cultured in cells that make it hard for them to repro-duce. The organism must adjust to the hostile environment, becoming less efficient at infecting people. Against: MMR, yellow fever, tuberculosis.

Dead vaccine:

The organisms are killed with heat, radiation, or chemicals, before they are used in the vaccine, so there is no risk of infection. However, the vaccine is not so efficient, so it is often necessary to vaccinate again Against: Flu, whooping cough.

Component vaccine:

Only contains the portions of a virus/bacterium that make the immune system react, such as proteins on the surface of the virus. Chemically extracted or produced with DNA technology. Against: HPV.