The invention relates to a formulation for supplementation on immune response to a biological substance. More particularly, the formulation consists of one or more forms of Vitamin E which provides a supplementation on immune response to tetanus toxoid. In addition, the present invention also relates on the effect of different types of Vitamin E such as tocotrienol rich fraction, delta tocotrienol and alpha-tocopherol supplementation on immune response to tetanus toxoid vaccination.