Malaria “has been killing children and sapping the strength of whole populations for tens of thousands of years. Now we can chart a course to end it.
Eradicating malaria is not a vague, unrealistic aspiration but a tough, ambitious goal that can be reached within the next few decades. – Bill Gates
Bill Gates called for the eradication of malaria in 2007. This week, the New England Journal of Medicine published the results of the phase 3 trial of a malaria vaccine by GlaxoSmithKleine (GSK) given to African children between 5- and 17-months old finding it to “provid[e] protection against both clinical and severe malaria.” In fact, the halved the risk of those vaccinated from getting malaria bringing us one step closer to eradicating the disease – perhaps for many countries in the next decade.
According to the National Library of Medicine:
Malaria is a parasitic disease that involves high fevers, shaking chills, flu-like symptoms, and anemia caused by a parasite that is passed from one human to another by the bite of infected Anopheles mosquitoes. Malaria be transmitted from a mother to her unborn baby and by blood transfusions. After infection, the parasites (called sporozoites) travel through the bloodstream to the liver, where they mature and release another form, the merozoites. The parasites enter the bloodstream and infect red blood cells. The parasites multiply inside the red blood cells, which then break open within 48 to 72 hours, infecting more red blood cells.
The CDC estimates that there are 300-500 million cases of malaria each year, and more than 1 million people die from it – many of them children in sub-Sarahan Africa. It can infect the brain, destroy blood cells, cause kidney, liver or repiratory failure, create meningitis or rupture the spleen leading to massive internal bleeding.
In some areas of the world, mosquitoes that carry malaria have developed resistance to insecticides and some to antibiotics.
Currently the World Health Organization lists the only interventions to control malaria as the prompt and effective treatment with artemisinin-based combination therapies; use of insecticidal nets by people at risk; and indoor residual spraying with insecticide to control the vector mosquitoes. But the some mosquitoes have developed resistance to insecticides and antibiotics. Thus, a vaccine could prove essential in eradicating this devastating disease.
Clinical trials for medicines are a very time consuming and expensive process (thus the pharmaceutical companies’ rationalization for how they price medications) preceding from pre-clinical studies to phases I-IV before they are available on the market. The phases help collect safety and efficacy data on a potential new medication.
According to clinicaltrials.gov:
In Phase I trials, researchers test an experimental drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
In Phase II trials, the experimental study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety.
In Phase III trials, the experimental study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the experimental drug or treatment to be used safely.
In Phase IV trials, post marketing studies delineate additional information including the drug’s risks, benefits, and optimal use.
So Phase III trials proving efficacy of a malaria vaccine is a pretty big deal as it may mean the realization of a eradicating malaria through vaccination, as we did with smallpox.
Challenges still remain. The vaccine is not as effect as many other vaccines for illnesses like polio. And the vaccine only goes after one of the four malaria carrying parasites – Plasmodium falciparum. Thus the vaccine may need to be combined with other interventions.
Even if future trials go well the vaccine may not be ready for use for 4 more years or more. And even then, the question becomes – who will pay for this vaccine? Certainly GSK will want to recuperate its costs for researching and developing the drug, but many of those affected by malaria cannot afford even basic necessities let alone new vaccines. So who will pay for the cost to live malaria free?
Certainly the advances in potentially eradicating malaria are amazing but there remains much work ahead.