Suppose a nation is attacked. In one scenario the nation has no army and knows nothing about the enemy. It has to mobilize, train troops, send out intelligence agents to find the enemy's weakness and then combat it. Such a nation is likely to lose before it can do all of this. In the other scenario the nation is expecting an attack, has a standing army ready for combat, and knows just how to fight the invader.
Victory is likely.
Suppose that you are ill or want to prevent illness. You can transfer the immunity of someone who already has a immune defense against your illness to you. That is what a transfer factor does. Cows are exposed to various disease causing organisms and they mount a defense against them. The agent that is responsible for the defense can be extracted from the bursa of the chicken and given to a person.