Candidate vaccine eliminates the deadliest strains of malaria

British scientists have developed a candidate vaccine that has shown the potential to eliminate all of the strains of the deadliest form of the malaria parasite.

The results of the research, led by a team from the Jenner Institute at the University of Oxford, have independently confirmed a discovery by scientists at the Wellcome Trust Sanger Institute of a target within the parasite that is being called a potential Achilles heel, according to MedicalNewsToday.

The Wellcome Trust Sanger Institute study, recently published in the journal Nature, showed that Plasmodium falciparum, the parasite responsible for nine out of 10 malaria deaths, relies on a single receptor to gain entrance into red blood cells.

The receptor, called basigin, is located on the surface a red blood cell. The parasite uses a protein, the antigen RH5, to attach to the receptor in order gain access to the cell, where it then grows and replicates, causing the potentially life-threatening disease.

"Our initial finding, reported last month, was unexpected and completely changed the way in which we view how the malaria parasite invades red blood cells," Dr. Gavin Wright of the Wellcome Trust Sanger Institute, a co-author on both studies, said, reports. "It revealed what we think is the parasite's Achilles' heel in the way it invades our cells and provided a target for potential new vaccines."

The new vaccine has been shown to induce an antibody response in animal models that neutralizes all of the tested strains of P. falciparum.

"We have created a vaccine that confirms the recent discovery relating to the biology of RH5, given it can generate an immune response in animal models capable of neutralizing many - and potentially all - strains of the P. falciparum parasite, the deadliest species of malaria parasite," Dr. Sandy Douglas, a co-author of the study, said, reports. "This is an important step towards developing a much-needed vaccine against one of the world's major killers."

The RH5 antigen appears to have little genetic diversity, which is a boost to vaccine researchers because it means that a single vaccine could be effective against many strains of the parasite. The researchers believe that people who have been exposed to malaria have generally had low levels of antibodies that target this particular antigen, meaning it has not had to evolve a great deal to remain successful.

"Vaccines against malaria are notoriously difficult to develop because the parasites' antigens - the target of vaccines - tend to be genetically so diverse," Professor Adrian Hill of the University of Oxford said, according to "The RH5 antigen doesn't show this diversity, making it a particularly good target for a vaccine to exploit. Our next step will be to begin safety tests of this vaccine. If these prove successful, we could see clinical trials in patients beginning within the next two to three years."