Computer-generated image of an antibody: Immunoglobulin E (IgE) is a class of antibody shown here as y shaped.  The body fights infections with antibodies, proteins produced by the immune system that help identify and neutralize pathogens. They recognize specific molecules on pathogens called antigens, bind to them and mark them for destruction. Antibodies can also neutralize pathogens directly by blocking their ability to infect cells or causing them to clump together for easy removal. Different types of antibodies work differently: IgM neutralizes pathogens, IgG provides long-term protection, and IgA protects mucosal surfaces. The immune system also creates memory cells that remember past pathogens, allowing for quick response in case of re-infection. Vaccines create these memory cells against one or more components of a virus or bacterium, preparing the immune system for real infection.