Fan fiction, also called fanfiction, is derivative fiction written using another author's characters and universe. Fanfiction authors write stories about their favorite characters from books, movies, or comics.
Antibodies, also called immunoglobulins, are proteins manufactured by the body that help fight against foreign substances called antigens. When an antigen enters the body, it stimulates the immune system to produce antibodies. (The immune system is the body's natural defense system.) The antibodies attach, or bind, themselves to the antigen and inactivate it. Every healthy adult's body has small amounts of thousands of different antibodies.
Vaccines are like a training course for the immune system. They prepare the body to fight disease without exposing it to disease symptoms. When foreign invaders such as bacteria or viruses enter the body, immune cells called lymphocytes respond by producing antibodies, which are protein molecules.