How Does A Vaccine Causes Resistance To A Disease?
Vaccines work on the basis of immunoglobulin development. Immunoglobulin is antibody to specific antigen. There are different classes of immunglobulin - IgG, IgM, IgA, IgD and IgE. Of these the majority are formed by IgG and IgM. With this basic information, I shall try and explain the whole process in brief and simple terms.
Vaccine is either a whole microbes or a part of the microbes which act as antigens. They are capable of producing same antibodies (immunoglobulin) as that of the original pathogenic microbe but do not cause infection. These antigens are presented to B-cells via antigen presenting cells. B-cell secretes Y shaped immunoglobulin - small amount of IgM and large quantity of IgG. This IgG immunoglobulin forms the majority of memory cells waiting to act against subsequent attacks from the same antigen (pathogenic microbes).
The effectiveness of immune resistance depends on the amount of IgG immunoglobulins which in turn depend on the amount of antigens presented to the B cells. Either if the number of B cells is low or if the amount of antigens presented is few, immune resistance developed will be insufficient to protect you against future infections. Thus most vaccines need to be boosted at timed intervals for maximum benefits.
I hope I am clear. I shall be glad to clarify if things are not clear.
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