On the Malaria Vaccine

November 7, 2011

A recent WHO report indicates that nearly a third of all countries affected by malaria are on course to eliminate the disease over the next 10 years. Though malaria can lead to complications or even death, it is a preventable and curable illness caused by a parasite that is passed from one human to another through the bite of infected Anopheles mosquitoes. Infected individuals frequently experience high fevers, flu-like symptoms, and anemia; and in 2008 malaria caused between 190 and 311 million clinical episodes and between 708,000 and 1,003,000 deaths. Anti-malarial medications, insecticidal nets, and other control and prevention measures have saved an estimated 1.1 million lives in Africa over the past 10 years, but the availability of an effective vaccine  is vital to halt its spread.

In the 109 countries and territories where the risk of malaria transmission is the greatest, newly developed malaria vaccines could save lives. Reports indicate that there were 225 million cases of malaria and an estimated 781,000 deaths in 2009, but these figures have steadily declined in recent years. Though preventative measures have helped to reduce infection rates, experts note that the development and use of a malaria vaccine could reduce them further. During a major clinical trial,  a recently produced experimental vaccine known as RTS,S halved the risk of children in Africa contracting malaria. Currently children under five years of age account for the majority of the 800,000 people who die each year as a result of malaria. According to the developers of the vaccine, the adverse effects observed during the vaccine trial are comparable to those seen in children receiving other vaccines.

The RTS,S vaccine triggers an immune response which targets the Plasmodium falciparum parasite that causes malaria. This immune response prevents the parasite from maturing and multiplying in the liver of the vaccinated individual. Unlike other previously developed malaria vaccines, this new vaccine has been created to target different forms of the disease and to trigger a range of antibody responses. Though researchers have been working for 40 years to develop an effective malaria vaccine, to date the outcomes have not been entirely successful. Additional research and testing of the RTS,S vaccine is needed, but according to Dr. Mary Hamel of the Centers for Disease Control and Prevention, “these findings show we are on track in the development of a vaccine.”

With further testing and refinement, this vaccine has the potential to save millions of lives each year and eradicate a disease that affects 3.3 million people – half the world’s population. An effective malaria vaccine could reduce malaria-related deaths, 89 percent of which occur in Africa, and could improve the lives of individuals in regions impacted by the diseases.

 

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