This is my answer off the top of my head, hope it helps.
Infectious diseases can be controlled using many methods. These methods vary depending on the situation at hand, however common methods include eliminating as most contact with the disease as possible and taking a dead piece of the disease and forming it into a vaccine ( much like everyday people are injected with a influenza shot so the immune system can analyze the threat and build defenses against it. )
Although scientists take the most measures to battle these threats, infections such as these are constantly evolving, in turn broadening our knowledge and working capacity to match up our strength to the disease.
