Vaccines Essay Example | Topics and Well Written Essays - 750 words

Vaccines - Essay Example Vaccines stimulate the immune system of the body and helps it recognize the agent as a pathogen or foreign, hence destroying it (Bona and Bonilla, 1996). Vaccines do not offer complete protection of the body against a certain disease; therefore, it is important to choose the most adequate type of vaccine in order to make it more responsive. To develop an effective immune against a dangerous virus, one must consider important aspects, which include the rate of maintaining high immunizations even when the disease is rare. Other factors to be considered include the impact of the immunization campaign on the epidemiology of the disease in the long term and the continuous surveillance of the disease due to the introduction of the new vaccine. An inactivated whole organism vaccine is produced by the killing or destruction of a disease causing organism by use of radiation, heat or chemicals (Reiss, 2005). It has several advantages since it is very stable and safe, which is an advantage over live vaccines, since the inactivated vaccines are killed and cannot mutate back to form the disease causing agent. They are advantageous since they do not require refrigeration hence their storage and transportation is easy, which makes it accessible for people in developing countries. Inactivated vaccines also have the main disadvantage of triggering a weak immune system response; hence several boosters are needed where as live vaccines stimulate a stronger one. This is a major set back to people in areas that are inaccessible to healthcare due to lack of boosters. Another set back is that the nonantigenic portions of the vaccines microbe may cause an inflammatory response to some people. Attenuated whole organism vaccines are live vaccines that contain the living microbe or the modified live viruses which are only weakened in laboratories in order to prevent diseases (Goldsby et al 2000). Viruses are attenuated by growth of generations in cells where they do not reproduce so well , the unsuitable environment makes them repel the viruses. As they grow they become weak due to the new environment and their natural host. They are the closest thing to natural infections hence they are good to the immune system. They stimulate strong antibody and cellular responses, and give lifelong protection with one or two doses. They are easy to create for given diseases like chickenpox. There are several setbacks to this immune system, for example the attenuated vaccines are live so they may revert and cause disease, and people with weakened immune systems for example HIV-positive people cannot use attenuated vaccines for their own protection. Attenuated vaccines need to be refrigerated therefore it is hard to store and transport them to under developed areas. They are difficult to create for bacteria, since bacteria have so many genes, therefore, it is hard to control them. Recombinant vector vaccines are also known as sub-unit vaccines, and are comprised of antigens which elicit the immune system best combined with the DNA of another (Murphy, Walport and Travers, 2008). They are mainly used for complex infections, are experimental and are similar to DNA vaccines though they use bacteria to bring out DNA to the cells in the body. Vector means the virus or a bacterium that is used as the carrier virus latches on to the cell and injects genetic material into the cell. Scientists take the genomes of harmless viruses and insert the genetic material in portions into the cells. The viruses ferry the microbial DNA to the cells. The recombinant vector vaccines cause a natural infection and, therefore, stimulate the immune system. Attenuated bacteria also play the role of vectors, where the genetic mater