viruses are used to produce vaccines for prevention of certain viral infections
The body's defense system. Most viruses do not cause serious diseases and are killed by the body's immune systemâits network of natural defenses. In many cases, people never even know they have been infected. But unlike bacteria, which can be killed by antibiotics, most viruses are not affected by existing medicines. Fortunately, scientists have been able to make vaccines, which help the body develop natural defenses to prevent many viral infections.