The Different Strategies Attempted to Develop a Vaccine against Malaria - Coursework Example

The Different Strategies that have been used to develop a vaccine against Malaria Name: Course: College: Tutor: Date: Abstract Thanks to advanced biotechnology and pharmacy Malaria has overtaken HIV Aids and tuberculosis to be one of the most contagious diseases on earth today. Today millions of people worldwide die from Malaria worldwide and still the budget constraints caused by this disease on public health facilities are enormous. Specifically 40% of the global population dies of this disease annually and the most affected in these deaths is third world countries. The disease is an emergency case in Africa where the death rates of children has soared over the years due to this disease. (Kristoff, 2007) Objectives People traveling from Malaria free zones to areas where the disease is prevalent are at a major risk of infection since they don’t have any form of immune at all. It’s unfortunate that the anopheles mosquito has been able to adopt and gain resistance against drugs and insecticides that are used against them thus throwing studies of control measures against this ticking time bomb already at the brink of precipitise into confusion. This forms the essence of this study to review the different strategies that have been used to develop a vaccine against. (Kristoff, 2007) Scope Since vaccinations started being developed various vaccines have been developed to curb the effects of Malaria. This paper reviews various studies that have been conducted and the strategies used to formulate vaccines against Malaria. Many of the vaccines were developed to limit the capacity of parasites infecting lots of red blood cells. (MVI, 2007) This still has a loophole where some red blood cells would still be infected. Thus the infection is still on but only it’s critical nature is reduced. The reason why vaccine formulation is still an ongoing initiative is because the most effective vaccine which destroys the parasite totally and protects the immune system against attacks is yet to be found. (MVI, 2007) The Strategies Malaria vaccines should be tried in three faces before they are used. This is done to ensure safety in the human body is observed and any adverse side effects noted and various mitigation mechanisms sought before proceeding with the trials. Fortunately the vaccinations strategies under progress today are proving to be more efficient in eliminating this scourge totally. (Kilama, 2007) The production of Malaria Vaccine is still a complex subject because the plasmodium parasite that causes it has a very intricate lifecycle. Thus development of various vaccines hover around its various life cycle stages to ensure that it’s eliminated before it starts to reproduce. The extraneous amplification of plasmodium once in the human blood cycle is the main threat to researchers. New sophisticated protein technology in addition to DNA vaccitology is being used to come up with a lasting solution to this enormous scourge. (Kilama, 2007) Asexual Blood Stage Malaria Vaccine The increase in morbidity and rates of mortality has changed the original eradication policy of WHO to that of control. The continual upsurge of Malaria is as a result of reappearance of parasite and insect transmitters that have adopted and become resistant to the measures being taken to eradicate them. (Genton, 2007)Due to these complexities researchers have directed their energies towards studying the bimolecular and the biochemical characters of the parasite so as to obtain an immunoprophylactic methodology that would ensure complete eradication of this parasite. This one has been tried already and it was developed to curb the plasmodium’s immune evasion as well as its broad antigenic formulation. (Genton, 2007) This vaccine was developed as a result of evidence suggesting the feasibility of malaria antigens despite immunity gained against them having been known to be periodic and species specific. The convincing part came when non immune volunteers from Papua New Guinea were infected and cured with blood parasites at very low doses became immune at more exposure and even illustrated reduction in number of parasite infection. (Mikolajczak, 2007) As a result of these findings researchers were convinced that this vaccine can reduce drastically the current death rates caused by malaria by inhibiting the number of parasites in the blood or expunging from the blood stream all parasites circulating in it. The strategic point of developing Malaria vaccines at the blood stage points is that immunity at this juncture would focus on the presence of CD4 T cells and antibodies. Thus vaccines induced at this point are capable of providing an immune system that will induce human and cell immunity. (Mikolajczak, 2007) The break through with this vaccine came when volunteers who weren’t immune who have gone through the process of being challenged and cured by blood stage parasites became immune to later challenges.Inaddition the asexual blood stage vaccines tested in an endemic area are very efficient in reducing the parasite intensity in kids. A Malaria vaccine that is recombinant will ends up reducing the density of plasmodium in the blood while increasing pressure on the population of parasites in the blood stream, leading to them completely expunged from the blood. (Mikolajczak, 2007) Preerythrocytic Stage Malaria Vaccine The Preerythrocytic stage is the period in which the parasite in form of a sporozyte enters the human blood stream and heads straight to the liver where it grows and on maturity starts multiplying profusely. Vaccines developed at this stage are aimed at curtailing the early stages of development of this parasite. The vaccines react in a way that prevents infections or attacks affected cells of the liver that are eventually infected. (Mikolajczak, 2007) Studies show that this is the most effective way of eradicating this scourge due to results got from immunization by radiation attenuated sporozytes for they resulted to lasting sterile security on all models challenged. Though the inhibiting factor remains the security concerns about its mass production without careful monitoring facilities being put in place. The light at the end of the tunnel are the recent breakthroughs in genetic Engineering and rapid developments in the process of manufacturing radiation attenuated vaccines. These developments will overcome the hurdles set by the biosafety of its current mass production. This vaccine has been tested and tried (Mikolajczak, 2007) It was strategically developed to provide an extended permanent spotlessly clean defense. By use of the current advanced genetic engineering technology the researchers were able to create live malaria vaccines thus removing the hurdles that previously inhibited its large scale production. (Druiluhe, 2007) Vaccines based on the epreerythrocytic stages of malaria have had the greatest impact on strategies aimed at curbing this life threatening scourge in the recent past. Due to safety concerns aggravated by the large scale production of live attenuated preerythrocytic units researchers decided to come up with a safer mode which involved the nature of attenuated protozoa in the human immune system. This is because the preerythrocytic stage results in induction of different cells to provide various immunity giving this Vaccine its added advantage. (Druiluhe, 2007) This strategy demands that vaccines formulated against this critical stage of the liver should provide enough CD4 and CD8 T Cells to battle the parasites and expunge them from the body before they reach the erythrocytes. This is because if they are not prevented in time from reaching the erythrocytes then destruction, pain and eventual deaths are imminent. Its here that CD 8+ is highly dependent to increase impunity. As a matter of fact the CD8+T Lymphocytes are vital for protection at this stage of Malaria infection and as a result of this crucial character researchers have strategies to make vaccines based on CD 8+ Cell response. (Kuk, 2007). Erythrocytic Stage Malaria Vaccine Malaria still is a big challenge to pregnant women and kids under the age of five in Africa and though finding an effective vaccine has been elusive concerted efforts are being put in place to ensure that finally this will be a thing of the past. The potential vaccines RTS, S could only but confer partial protection in its face two of trials and is currently undergoing face three trials in Africa. More efforts need to be directed towards identifying new vaccine targets to accelerate the chances of creating an effective Malaria vaccine. (Druiluhe, 2007) Most vaccines are made in such a way as to prevent the plasmodium parasite from infecting a large number of red blood cells. As much as this doesn’t prevent infections it reduces the mortality rate. Since much has been gathered about the biology of this parasite advanced technology assists in creating the best vaccine against it. As much as over the last four years nothing concrete has come out of the laboratories where various tests are performed to come up with vaccines against Malaria. (Druiluhe, 2007) The current tests could be the answer that the world has been waiting for all along. The reason being they provide deep answers on the life of this parasite and gives lee ways in which it can be tamed. This vaccine relies on the erthrocytic stage of the malaria vermin. At this stage some helical coiled protein domains are present in the parasite and it’s these ones that are used by the vaccine. (Villard, 2007)The synthesized peptides are usually structurally similar as the natural ones. Strategically the peptides produce specific antibody reactions in immunization trials yet there is no cross reaction of the antibodies for other peptide specifications. Since research has shown that the chosen peptides have some kind of helical content whether minute or very high the use of chemical and bioinformatics research here would result in the identification of molecules that target biologically active antibodies resulting in the final formation of a Malaria vaccine in the erythrocytic level. (Villard, 2007) Mosquito Stage Malaria Vaccine This disease is caused by a parasite species called plasmodium. There four kinds of malaria which are Plasmodium ovale, Plasmodium falciparum, Plasmodium Malariae and Plasmodium vivax.Of these Plasmodium falcipareum is the deadliest infection followed by Plasmodium vivax. This parasite is transmitted to human bodies through the bite of a female anopheles mosquito. (Villard, 2007) Sporozytes are the parasites that feed on an individual causing Malaria after they enter an individual’s blood stream as soon as he is bitten by a mosquito. Once in the blood they go immediately to the liver where they will mature in a week’s time. The extraneous multiplication of porosities forms mezozytes that invade the red blood cells on bursting from the liver. It’s this increase in parasites in the blood stream that results to Malaria. (Miura, 2007) Transmission blocking strategy could be a workable solution if implemented today rather than wait for ages for a working vaccine. Here sexual stage parasites are prevented from infecting mosquitoes by human antibodies. It’s a very promising kind of vaccine otherwise known as transmission blocking vaccine. They are formulated mainly to come up with an immune response system in the body of their hosts. As a matter of fact this immune response blocks the parasites growth into a mosquito’s carrier thus inhibiting the eventual transmission of the parasite. (Miura, 2007) Also proteins on the surface of the gametes are exposed by the parasites while still within the body of the host human being. Natural antibodies if directed towards these proteins can be verified in persons living in areas where the prevalent rates are very high. Even during subsequent stages of parasite evolution more transmission blockers can be found. Thus the logic behind this strategy is to prevent spreads of infection by inhibiting infection in the transmission vector. The impact of this vaccine is big because apart from providing crowd immunity it ensures that it affects the course of infection in vaccinated individuals. Apart from this it has the capacity to kill the target outside the host’s body. In this regard suffice it to say that it protects mosquitoes by an inactive immunization procedure that is activated by antibodies taken in the mosquito’s food i.e. human blood. (Miura, 2007) Conclusion Malaria is responsible for millions of deaths world wide every year. And the highest mortality rate happens in Africa for children under the age of five years. The extraneous resistance of Malaria parasites to available drugs and the adaptation of a defense mechanism by mosquitoes to insecticides have necessitated various strategies to come up with a long-lasting solution to this weapon of mass murder that is threatening the extinction of families in Africa and other places in the world today. (Miura, 2007) As much as the journey towards a successful vaccine has and is still bumpy due to various factors such as wide polymorphism of various target antigens and the failure of most vaccines to enlist long lasting immunology in the host. This paper concedes that vaccines that have been adopted as a result of strategically initiated research mechanism should and will be able to provide naturally acquired immunity in populations where the scourge has high prevalent rates. REFERENCES Druilhe, O. and Barnwell, J. W. 2007. Pre-erythrocyte stage malaria vaccines: time for achange in path. Current Opinion in Microbiology Retrieved from: aosite.lb.nagasaki u.ac.jp/dspace/bitstream/10069/.../Ecology90_2414.pdf on 26 May 2011. Genton, B. and Reed, Z. 2007. Asexual blood-stage malaria vaccine development: facing the Challenges. Current Opinion in Infectious Diseases 20:467-475.Retrieved from; journals.lww.com › Home › October 2008 - Volume 21 - Issue 5 on 26th may 2011. Kilama, W. 2007. Malaria- a serial killer. http://www.malariavaccine.org (accessed May 26, 2011). Kristoff, J. 2007. Malaria stage-specific vaccine candidates. Current Pharmaceutical Design13 (19):1989-1999. 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