Concision- A cutting up or off; compactness
Prejudice- An unfair feeling of dislike for a person or group because of race, sex, religion, etc.
Minority- The group that is the smaller part of a larger group
Loathed- To hate (someone or something) very much
Robert Neville is saying that Vampires are the minority.
They are disliked and hated because of their notorious actions.
They are prejudice against because, in concision, they kill people and suck their blood.
In this novel, vampires are the majority as the disease has made everyone convert into vampires. The minority are humans because there is only one left, Robert Neville.