The body responds to a pathogen by the protection systems’ first line of defense.The first line of defense in opposition to many typical microorganisms are macrophages and neutrophils which belong to the innate immune system. These cells are fundamental for the regulation of common bacterial infections, none the less, they cannot always defeat infectious organisms, and there is a portion of pathogens that theycannot distinguish (Janeway Jr et al., 2001). The fundamental penetration of the exteriorepithelial barrier of the body by microorganisms such as bacteria are promptly met by cells and molecules which can build an innate immune response. The defense against bacteria is directed by phagocytic macrophages by the process of surface receptors which can recognize and confining common components of many bacterial surfaces. Triggering the macrophage to encompass the bacterium is the job of bacterial molecules that attach to the receptors. They also promote the discharge of biologically active molecules. Proteins that are called cytokines are secreted from stimulated macrophages, affect the conduct of other cells that carry receptors for them (Janeway Jret al., 2001). Instantly, from a pathogen attack on living things, innate immune systems get turned on. Physical obstacles like skin, deterrence mechanisms like discharge of mucusand general systems like cellular response are components of the innate immune system. This immune response is non-specific. Phagocytes which devour the pathogens, mast cells which discharge histamines and cytokines to generate an inflammatory cascade, eosinophils, which produce chemicals to wipe out the pathogens, natural killer cells dismantle the infected cells to limit the disbursement of a disease or infection, macrophages which discharge cytokines, neutrophils which are phagocytic cells, basophils which give off histamine and dendritic cells which areantigen displaying cells; are all the cells that are assisting in the innate immune system (Marieb & Hoehn, 2011). The slower response is adaptive immunity, it is specific and can distinguish pathogens from non-pathogens. B lymphocytes and T lymphocytes are the cells presentin an adaptive immune response (Marieb & Hoehn, 2011). By producing antibodies in counter to a pathogen B cells participate in humoral immunity. Cell mediated immunity iswhere cells perform. Cytotoxic T cells, Helper T cells, and Regulatory T cells are the diversified types of T cells. Cell mediated immunity can be obtained by a someone who has not been threatened by a particular pathogen through cytotoxic T cells and Helper Tcells from and individual who has been susceptible to that pathogen before (Marieb & Hoehn, 2011). Cytotoxic T cells, B lymphocytes and other immune cells are activated byHelper T cells. Cells that are infected along with pathogens are removed by cytotoxic T cells, this system is kept in balance by regulatory T cells so as to prevent an autoimmune response.The slower response is adaptive immunity, it is specific and can distinguish pathogens from non-pathogens. B lymphocytes and T lymphocytes are the cells presentin an adaptive immune response (Marieb & Hoehn, 2011). By producing antibodies against pathogens, B cells participate in humoral immunity. Cell mediated immunity is where cells perform. Cytotoxic T cells, Helper T cells, and Regulatory T cells are the diversified types of T cells. Cell mediated immunity can be obtained by a someone who has not been threatened by a particular pathogen through cytotoxic T cells and Helper Tcells from and individual who has been susceptible to that pathogen before (Marieb & Hoehn, 2011). Cytotoxic T cells, B lymphocytes and other immune cells are activated byHelper T cells. Cells that are infected along with pathogens are removed by cytotoxic T cells, this system is kept in balance by regulatory T cells so as to prevent an autoimmune response. At the introduction of a pathogen to the body, it responds by the protection systems' first line of defense. Antibodies are formed by the immune system ina counter to the foreign antigen, this type of immunity is called active immunity. Longer periods of protection are achieved by Active immunity (Janeway Jr et al., 2001). The actions of B cells, lymphocytes and T cells are what the acquired immunity is mainly dependent on. Antigen receptors on the exterior of B cells and T cells are antigen-specific, and each lymphocyte has specific. In the spleen or a lymph node the B cells get triggered when the specific antigen attaches to its specific B-cell receptor (Marieb & Hoehn, 2011). After the antigen attaches to its specific B cell receptor B cells go throughclonal expansion and divide by mitosis many times. Several copies of B cells are made and most of the reproduced cells convert themselves into plasma cells, which circulate in the blood and lymph. Some of the reproduced B cells are remodeled into memory cells, these are extremely crucial for long-term immunity (Janeway Jr et al., 2001).After the first display of a foreign antigen a primary response is developed,antibodies are not present for a few days, shortly afterward there is a surge in theantibodies. After a second presentation of the pathogen a secondary response isdeveloped, at this second time of exposure, the immune response is remarkably high,the second exposure is also known as a booster (Marieb & Hoehn, 2011).) Promptingthe immune system is MMR vaccine reasons against the diseases and viruses byproducing antibodies against them. Our bodies keep this in their memory, so ourimmune systems easily recognize the pathogen in future and wipe it out with antibodies.this case of being infected by a previously undiscovered pathogen will not receive anybenefits from an MMR vaccine, Furthermore, since the person is affected bytransmission their immune system is weak and in this predicament an MMR vaccinemight incite more problems. A mild form of the infection caused by measles, mumps andrubella could develop because the vaccine contains a live attenuated virus.Lymphoid compartment of lymph nodes is imperious to countless molecules which are transported via lymphatic vessels. Fibroblast reticular cells within the lymphoid compartment, shape an interconnected system, the conduit system (Ramon, et al. 2008) This system carries soluble antigens away from lymph to T