The Lymphatic System fights against diseases by fighting pathogens, or viruses and bacteria that make your body sick. When the Lymphatic System fights pathogens, it helps fight pathogens which give you a chance unlikely to get a disease.
This is because once you immune system fights off the disease. Your body has adapted to protect yourself from that certain disease. However, not every disease is caught only once - this is because the disease effectively 'top trumps' the immune system.
Vaccinations are dead cells of the disease. When it enters the body, the body 'fights' the disease without hurting the body. The body then builds up a defense system against this disease and is ready if and when the disease really happens.
The immune system is a system of biological structures and processes within an organism that protects against disease. The system that attacks germs and help to fight off infections is called the Immune system.
One way the immune system fights diseases is by calling out white blood cells to kill the disease. another way that the immune system fights off diseases is by making your body temperature higher so that the heat can de-nature and kill that organism.