A microantibody is an artificial short chain of amino acids copied from a fully functional natural antibody.
[1] Antibodies are produced naturally by the body and play a key role in fighting infections caused by bacteria and viruses.
[2] The use of whole, natural antibodies as medicines presents many problems: they can only be produced by live cells and this process is difficult to control on an industrial scale, they are large molecules and following administration by injection, they do not diffuse easily from the blood to the tissues and other sites of infections where they are needed.
They can be chemically synthesized and their small size allows them to leave the blood circulation quickly and reach the sites of infections in the tissues.
[4] Vaccines are used to prevent infections by stimulating the body's own immunity, which includes the production of antibodies that destroy infectious agents such as bacteria and viruses.