Current Status of Malaria Vaccinology
Current Status of Malaria Vaccinology
In order to assess the current status of malaria vaccinology one must first take an overview of the whole of the whole disease. One must understand the disease and its enormity on a global basis.
Malaria is a protozoan disease of which over 150 million cases are reported per annum. In tropical Africa alone more than 1 million children under the age of fourteen die each year from Malaria. From these figures it is easy to see that eradication of this disease is of the utmost importance.
The disease is caused by one of four species of Plasmodium These four are P. falciparium, P .malariae, P .vivax and P .ovale. Malaria does not only effect humans, but can also infect a variety of hosts ranging from reptiles to monkeys.
It is therefore necessary to look at all the aspects in order to assess the possibility of a vaccine.
The disease has a long and complex life cycle which creates problems for immunologists. The vector for Malaria is the Anophels Mosquito in which the life cycle of Malaria both begins and ends. The parasitic protozoan enters the bloodstream via the bite of an infected female mosquito. During her feeding she transmits a small amount of anticoagulant and haploid sporozoites along with saliva. The sporozoites head directly for the hepatic cells of the liver where they multiply by asexual fission to produce merozoites. These merozoites can now travel one of two paths. They can go to infect more hepatic liver cells or they can attach to and penetrate erytherocytes. When inside the erythrocytes the plasmodium enlarges into uninucleated cells called trophozites The nucleus of this newly formed cell then divides asexually to produce a schizont, which has
6-24 nuclei.
Now the multinucleated schizont then divides to produce mononucleated merozoites
. Eventually the erythrocytes reaches lysis and as result the merozoites enter the bloodstream and infect more erythrocytes. This cycle repeats itself every
48-72 hours
In order to assess the current status of malaria vaccinology one must first take an overview of the whole of the whole disease. One must understand the disease and its enormity on a global basis.
Malaria is a protozoan disease of which over 150 million cases are reported per annum. In tropical Africa alone more than 1 million children under the age of fourteen die each year from Malaria. From these figures it is easy to see that eradication of this disease is of the utmost importance.
The disease is caused by one of four species of Plasmodium These four are P. falciparium, P .malariae, P .vivax and P .ovale. Malaria does not only effect humans, but can also infect a variety of hosts ranging from reptiles to monkeys.
It is therefore necessary to look at all the aspects in order to assess the possibility of a vaccine.
The disease has a long and complex life cycle which creates problems for immunologists. The vector for Malaria is the Anophels Mosquito in which the life cycle of Malaria both begins and ends. The parasitic protozoan enters the bloodstream via the bite of an infected female mosquito. During her feeding she transmits a small amount of anticoagulant and haploid sporozoites along with saliva. The sporozoites head directly for the hepatic cells of the liver where they multiply by asexual fission to produce merozoites. These merozoites can now travel one of two paths. They can go to infect more hepatic liver cells or they can attach to and penetrate erytherocytes. When inside the erythrocytes the plasmodium enlarges into uninucleated cells called trophozites The nucleus of this newly formed cell then divides asexually to produce a schizont, which has
6-24 nuclei.
Now the multinucleated schizont then divides to produce mononucleated merozoites
. Eventually the erythrocytes reaches lysis and as result the merozoites enter the bloodstream and infect more erythrocytes. This cycle repeats itself every
48-72 hours