Question

Type a 1 page notes or information on Pathogenesis of Malaria and Update on Vaccine Research. Do not write the notes type it.

Answer 1

Type a 1 page notes or information on Pathogenesis of Malaria and Update on Vaccine Research. Do not write the notes type it.

Ans. Malaria is disease caused by a parasite named plasmodium and there are about four strains that infect humans When female anopheles Mosquito bites a person this pathogen is released into human. The history of malaria involves cyclic stages of infection between human and female anopheles mosquito. Initially this parasite enters the liver of human where it multiplies and then enters the blood circulation and infects R.B.C’s. The parasite grows inside the red blood cells and destroys them releasing daughter parasites that infect other red blood cells.

The symptoms of malaria occur when parasite invades R.B.C’s. During blood feeding stage, the female anopheles mosquito ingests these parasite. They mate in the gut of the mosquito resulting in their growth and multiplication.  After staying for 10to18 days in the gut of mosquito, the parasite migrates into the salivary glands of mosquito in the form of sporozoite.When this mosquito feeds on blood of another person the anticoagulant saliva along with sporozoite enters blood stream of another person and then migrate into liver, where the new life cycle of parasite begins. The pathogenesis of this parasite occurs in two stages exoerythrocytic stage and erythrocytic stage.

Exoerythrocytic stage:

• The exoeyrthrocytic stage begins when the female anopheles mosquito bites a person and the plasmodium spp is released into the blood stream of a person as sporozoites.
• They travel through the blood stream into the liver, as sporozoites, where they multiply asexually for 7-10 days and mature into hepatic schizonts.
• The person is usually asymptomatic in this period.

Erythrocytic stage:

• The erythrocytic stage begins when merozoites are released into the blood stream from hepatic schizonts.
• These merozoites infect the red blood cells(R.B.C’s) and later develop into trophozoites that can feed on red blood cells.
• The trophozoites multiply and develop into schizonts which again release more number of merozoites that can infect more parts of the body.

Update on vaccine research.

Malaria happens to be the most dreadful disease affecting the life of many people and finally leading to the death. There has always been a constant approach in developing vaccines against this disease, However it has not been successful because of the complexity in parasite.

Many types of strategies for the development of vaccine against have been introduced and they include vectored vaccine, antibody based vaccine, whole sporozoite vaccine, erythrocytic vaccine, sexual stage vaccine, sub unit vaccine, conjugate vaccines, synthetic peptides , but the success has been limited.

There are several vaccines that have been sent for clinical trial but failed because of the three different life stages of the parasite.

Although vaccines have proved to decrease the incidence of many diseases, it has always been a challenge for developing vaccine against malaria. Parasite vaccines are always challenging because they generate low immunity and they need proper adjuvants . Most of the malaria antigens that have been chosen as vaccines show genetic polymorphism and become targets of natural immunity

While developing vaccines against malaria several factors like pathogen life cycle, epidemiology immune control and evasion, vaccine formulation, preclinical and clinical trials should always be kept in mind.