Need for malaria vaccine grows as climate change threatens disease spread

As climate change threatens to heighten the burden of malaria worldwide, a new study reports that a malaria vaccine may soon be on the horizon.

The recent discovery of a single protein deemed essential to the spread of malaria provides clues for vaccine design, but Thomson Reuters analysts say challenges remain for developing a vaccine against the mosquito-borne disease.

Dubbed AP2-G, the protein is necessary for switching on genes that are essential for the development of sexual forms of the malaria parasite that enable the transmission of the disease. This developmental change from asexual forms to sexual parasite entities is crucial in the transmission of malaria because it is the only stage that is infectious to mosquitoes. The findings were described in a February study published in Nature.

"Our studies discovered that if we switch off AP2-G in a parasite cell, then that cell cannot grow into a sexual-stage parasite," said Dr. Andy Waters, University of Glasgow, as quoted by the Thomson Reuters analysis. "This means that the parasite cannot move from the infected person back into the mosquito to continue the cycle, making transmission of that parasite from one human to another impossible."

Researchers believe that AP2-G's discovery could boost efforts to develop a sexual-stage vaccine that would help an infected person mount an immune response to prevent their malaria parasites from being transmitted to a mosquito and thus, to another person.

Meanwhile, a separate study that appeared in Science found that rising temperatures facilitate the spread of mosquitoes that carry malaria, underlining the need for a vaccine against it. The study, published in March, indicates that climate change will allow malaria-infected mosquitoes to spread to mountain areas unless preventive health measures are implemented.

Though mortality for malaria declined 45% between 2000 and 2012, the World Health Organization estimated that 3.4 million people still live with the risk of disease caused by the bite of a mosquito that lives in tropical climates, especially those in sub-Saharan Africa. At the same time, increased world travel means that historically low-incidence areas like the U.S. or in Europe and mountainous regions of Africa and South America are being exposed to more malaria.

The report estimates that a sustained level of global investment of $750 million to $900 million per year will be needed to adequately fund new malaria control tools--such as drugs, vaccines and diagnostic technologies.

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