Germs account for less than 5 percent of all microbes.
Usually your body and other microbes on your skin squelch the invaders. But sometimes the germs multiply too quickly, or your body is too run down to keep up a defense. Then, harmful microbes get into your system, and you get sick.
Once infected, though, your body fights back. If germs enter your bloodstream, special white blood cells gobble up or dissolve the invaders. Your immune system also produces antibodies to resist specific diseases in the future. For example, antibodies for measles make sure you won’t catch the disease again.
Doctors can give you a vaccine, and you won’t develop certain diseases—ever! Vaccines help your body produce antibodies by giving you a dead or weakened form of the disease-causing germ. However, the best infection protection is washing your hands!