Tuberculosis: and the trials for the development of a new vaccine Elena Charalambous
University of Bedfordshire
Tuberculosis (TB) is a serious disease and it mostly attracts the fields of immunology, pathology, radiology, respiratory physiology, and neonatology (Lawn and Zumla 2011). Tuberculosis is a very old disease it first affected the mammoths and Egyptian mummies and after that it infected a large amount of the mankind (Migliori et al., 2010). More specifically, TB is a bacterial infection derived by Mycobacterium tuberculosis, which is spread when exposed to aerosolize droplets and causes inflammation by invading the tissue (Migliori et al., 2011). TB most commonly affects the respiratory system, mainly the lungs but it is also possible to spread to other systems such as musculoskeletal, lymphatic, cardiovascular, neurological, gastrointestinal, or genitourinary (Migliori et al., 2011). TB infection may remain latent and not cause any symptoms, or become active. The occurrence of TB can be increased due to epidemic diseases such as AIDS, that makes patients more vulnerable to TB infection, this is mostly seen in sub-Sahara Africa (Migliori et al., 2011). Despite the seriousness of the Tuberculosis disease it is possible to make a full recovery from some types of TB with the appropriate treatment. From the last 10 years a massive increase in developing new potential tuberculosis vaccines has been seen. Most information about new vaccines and how they can reduce disease progression has been provided from some animal models, such as the mouse and guinea pig, those two models have also given the information on the pathology of the disease (Orme et al., 2005). However, not many things are given about the immunological level, specifically the nature of the T-cell response, which is necessary to confer long-lived resistance (Orme et al., 2005)
Robert Koch a German scientist was the developer of Mycobacterium tuberculosis was the one who discovered the first vaccine against tuberculosis (TB) in 1882 (Daniel, 2005). However the death of 123 selected cases made the people to believe that the new cure was a catastrophe (Daniel, 2005). Later on it was identified that the substance, which was used as vaccine therapy and created hype, was tuberculin (Daniel, 2005). Nowadays it is well known that TB, is a very complicated disease. Furthermore, despite the best efforts of researchers those five decades using effective drug programs the perfect vaccine against TB is not yet to be found (Tyagi et al., 2011). The Mycobacterium tuberculosis as mentioned above is a composed by different organisms, which can cause human disease, it consists, Mycobacterium africanum, Mycobacterium bovis, Mycobacterium microti, and Mycobacterium canetti (Tyagi et al., 2011). Because of all the human tuberculosis deaths caused by Mycobacterium bovis in Europe the laboratory strain of Mycobacterium bovis led to the development of the BCG vaccine (Lawn and Zumla 2011).
Moreover, BCG is the current tuberculosis vaccine, and it has shown that it has a steady protection against the childhood form of TB particularly in meningitis. The problem is that, the immunological memory that BCG makes has limited life and its effectiveness against an adult or an elder is significantly debatable (Lawn and Zumla 2011). Even though it has been in use for more than 85 years it is still unknown the reason that BCG works in some populations and in others it fails (Lawn and Zumla 2011).
It is very challenging and difficult to develop a new vaccine against Mycobacterium tuberculosis because it has some special features (Connell, D. W et al., 2011) From years of studying this disease it has been observed that the amount of people who are infected with M. tuberculosis and develop the disease is minor (approximately 10%), and this shows that most people are resistance to the attack of the TB disease (Connell,...
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