Vaccine development against malaria

Nardin E H, Nussenzweig R S (1993). T cell responses to pre-erythrocytic stages of malaria role in protection and vaccine development against pre-erythrocytic stages. Annu. Rev. Immunol. 11 687-727. 

Two major diseases, malaria and AIDS, are still out of control vaccines are not available, while the malaria parasite and the HIV virus, responsible for AIDS, have developed resistance to current dmgs. Variability of the agent, lack of commercial interest, and perhaps also unconfessed political plans at population growth control, have been an obstacle to active immunization against malaria. The hope for an HIV vaccine is now from the engagement of Merck Co (Conference 2001). 

Vaccines need to be developed against diseases with high mortality rates, such as AIDS, pneumonic plague, acute respiratory infections, diarrhea, and parasitic diseases such as malaria. 

There is no vaccine against malaria. It mutates readily, making it hard for a vaccine to be effective. The disease is treatable in most cases, but easily develops a resistance to drugs. The result is that in Sub-Sahara Africa alone the disease eliminates 70% more life than all cancers in all the developed countries combined. 

Malarial infection does not produce immunity in patients, and active research has been initiated to develop a malaria vaccine. " A vaccine that blocks the entry of sporozoites into the liver cells will prevent malaria at this stage. However, immunity to sporozoites does not protect the host against parasites in the erythrocytic cycle. Infective sporozoites of P. falciparum are covered by a polypeptide, circumsporozoite protein. Isolatiou aud ideutification of the gene encoding for this circumsporozoite protein have led to the development of a monoclonal antibody by recombinant DNA technology P. falciparum sporozoite vaccine is now under investigation. ... 

Whereas AIDS andHIV was only chosen as examples that contributes any imaginable difficulty to vaccine development. Table 2 also lists many other current vaccine projects and their specific difficulties. A limited number of different serotypes may still be overcome by making and combining several similar vaccines, once a successful vaccine against one of these has been accomplished. Thus, vaccines against parainfluenza infections appear reasonably feasible. Other indications, such as malaria, herpesvirus infections or Lyme... 

Although acquired immunity to some parasitic diseases may lower the level of infection, absolute immunity as seen in bacterial and viral infections is seldom seen in parasitic diseases. Since parasitic infections produce a wide variety of antigens because of the many life cycle phases, it is more difficult to identify a constant antigenic protein against which specific antibodies are protective. However, malaria remains a likely candidate for a vaccine and there are ongoing studies to develop one. 

The feasibility of developing a human malaria sporozoite vaccine was demonstrated in a clinical trial by using irradiated sporozoites as antigens. Protection against sporozoite infection apparently can be achieved by inducing a high titer of antisporozoite antibodies. It is currently presumed that it is only during the brief period (a few minutes or hours) when the sporozoite resides in the blood that antibodies... 

Some examples of research under development include a synthetic conjugated polysaccharide vaccine against Haemophilus influenzae type B, which has been described in 2004 (O Fig. 34). The vaccine prototype was obtained by conjugation to human serum albumin (HSA) [173]. Furthermore, very recently a malaria vaccine has been suggested [174] which is based on the total synthesis of the malaria toxin responsible for the morbidity and mortality associated with malaria. The malaria parasite expresses a large amount of glycosylphosphatidylinositol... 

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