Friday, November 11, 2011

Malaria Vaccine Possible By 2015

Science & Health


AIDS and malaria and TB are national security issues. A worldwide program to get a start on dealing with these issues would cost about $25 billion... It's, what, a few months in Iraq.
Jared Diamond
 
We would have wished that we could wipe it out, but I think this is going to contribute to the control of malaria rather than wiping it out.
—Tsiri Agbenyega
, a principal investigator
in the RTS.S trials in Ghana,
said about the trial vaccine

There were many ups and downs and moments over the years when we thought can we do it? But today I feel fabulous. This is a dream of any scientist —to see your life's work actually translated into a medicine that can have this great impact on peoples' lives. How lucky am I?
Dr. Joe Cohen, microbiologist, GlaxoSmithKline, and inventor of the RTS.S drug,
after positive results of Phase III clinical trials, Oct 18, 2011

Female Anopheles albimanus mosquito feeds on a human host, becoming engorged with blood. Anopheles adults also generally feed in the evening, or early morning when it is still dark. This species is a vector of malaria, predominantly in Central America.
Photo Credit: James Gathany, U.S. Centers for Disease Control and Prevention, 2005.
Source: Wikipedia


There is currently no effective vaccine against malaria, a parasite that kills hundreds of thousands of children each year. But there is promising results in clinical trials, and a vaccine (called RTS.S) might be commercially available by 2015 (See here and here). Even so, this vaccine might not become as effective as other long-standing vaccines like the ones to prevent polio or measles, mumps and rubella. The chief reason is that malaria is caused by a parasite and not a virus.

"Malaria is caused by a parasite called Plasmodium, which is transmitted via the bites of infected mosquitoes," explains the World Heath Organization. There are four species of the Plasmodium, with Plasmodium falciparum "the most widespread and dangerous," says a science site dedicated to microbiology.  Alphonse Laveran, a French army surgeon, was the first to notice parasites in the blood of a patient suffering from malaria in 1880. For his work,  Dr. Laveran was awarded the Nobel Prize in Medicine in 1907.

Even so, malaria persists in all about 100 countries in the world, chiefly in sub-Saharan Africa, where the greatest group at risk are children under the age of five. Effective treatment is available with the use of antimalarial drugs, including the use of artemisinin, which are called artemisinin-combination therapies, or ACTs.

Even so, a vaccine will decrease malaria deaths, particularly when used in conjunction with current practices, such as the use of bed nets and controlling the vegetation around waterways where female malaria-carrying mosquitoes breed—all of which are from the genus Anopheles (e.g., see here). Note it is only female mosquitoes that transmit malaria, since males do not bite humans and feed only on the juices of plants.

It`s not all bad news in regions where malaria has long been prevalent, notably Africa. Methods of eradication and vector control have already proven somewhat successful. In a May 2011 article in Time magazine,"Progress Against Malaria in Africa Is Real but Fragile," Ellen Johnson Sirleaf, president of Liberia; and Robert B. Zoellick, president of the World Bank, write:
More welcome news: global deaths from malaria have fallen from nearly a million a year in 2000 to 781,000 in 2009. But even while we mark what may be a turning point in our effort to eradicate the disease, we cannot overestimate our progress. It is fragile.

Malaria continues to exact a great toll, killing three-quarters of a million people a year, more than 90% in Africa, which accounts for about one in six child deaths. The consequences of losing our focus now would be deadly. Mosquito bed nets last about three years, and a failure to replace the more than 300 million nets blanketing Africa over the coming three years could lead to resurgent malaria illness and deaths.
That makes the availability of a vaccine more pressing, more urgent. If all goes well, GlaxoSmithKline, the pharmaceutical company responsible for the malaria drug (RTS.S), says the vaccine could reach the market in 2015.

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