Feb. 10, 2010, 10:31 a.m.
Tuesday, January 19, 2010
Scientists have identified a group of proteins they say could form the basis of a malaria vaccine, Australia's ABC News reports. "However, they say more laboratory work and clinical trials need to be done, with a vaccine at least 10 years away," the news service reports (Macey, 1/19).
As reported in the journal PLoS Medicine, researchers reviewed and synthesized data from previous studies that examined "the relationship between antibodies produced by the human immune system in response to malaria infection and the ability of these antibodies to protect against malaria," according to a press release from the Walter and Elisa Hall Institute of Medical research.
The press release continues: "Malaria parasites burrow into red blood cells by producing specific proteins. Once inside red blood cells, the parasites rapidly multiply, leading to massive numbers of parasites in the blood stream that can cause severe disease and death." The researchers from Walter and Eliza Hall Institute in Melbourne and the University of Melbourne discovered that the proteins, "produced by malaria parasites during the blood-stage … are effective at promoting immune responses that protect people from malaria illness," the press release writes (1/19).
"Malaria kills more than one million people a year and is the biggest cause of death in children under the age of five, mostly in developing countries," ABC News reports. The article also addresses challenges scientists have faced in attempting to create an effective malaria vaccine (1/19).
In related news, VOA News examines efforts underway to develop transmission-blocking vaccines (TBV) that prevent the mosquitoes that carry the malaria virus from spreading it. This approach will be the focus of a new collaborative between the Malaria Vaccine Initiative (MVI), Johns Hopkins Bloomberg School of Public Health and the Sabin Vaccine Institute, the news service notes (DeCapua, 1/18).
"Traditional vaccines work by introducing a killed or weakened version of a disease into the body, where the immune system spots it and cranks out antibodies against it. Then, if a wild strain of the pathogen comes along later – one that has the power to sicken or kill – the body is ready for it. The new approach is different … it would instead work within the mosquito gut," TIME writes. Rhoel "Dinglasan [of Johns Hopkins University] has found an antigen, called AnAPN1, that causes humans to create antibodies that prevent transmission of malaria by mosquitoes. Get enough of these antibodies into mosquitoes, and you lock the disease up there and prevent it from infecting us."
Instead of trying to come up with a way to vaccinate mosquitoes, "you put the AnAPN1 into their food source: us," the magazine explains. The article goes on to examine the challenges associated with TBV: "People would have to step forward to receive a vaccine that would not make them immune to malaria; they would instead become part of a growing web of people who would eventually push the parasite out of circulation" – and how researchers are working to make TBV more attractive to participants by delivering it in combination with other vaccines (Szalavitz, 1/15).
"Although eradication is a very long-term and aspirational goal, we are excited by the potential of transmission-blocking vaccines to significantly limit the spread of malaria infection," Christian Loucq, director of MVI, said in a statement (.pdf). "In combination with other interventions, we believe a successful [transmission-blocking vaccine] would provide another important tool in the fight against malaria" (1/15).
Gazette.Net adds details about the collaboration, including how the groups will be working together on the project, and includes comments from Sanaria CEO Stephen Hoffman on TBV and his company's vaccine efforts (Rand, 1/18).
The Kaiser Daily Global Health Policy Report is published by the Kaiser Family Foundation. © 2010 Henry J. Kaiser Family Foundation. All rights reserved.