Has the First Malaria Vaccine Been Discovered?

A fun way to divide a group of trivia enthusiasts is to ask them what the most dangerous animal in the world is. Those who received their formative educations courtesy of childhood favourites such as Jaws or Arachnophobia will probably throw the accolade  to the Great White Shark or some breed of eight-legged creepy-crawly. It’s easy to spot the Discovery Channel fans of the group because they will offer up the slightly-less pedestrian Hippopotamus as their answer. Despite their mostly herbivorous diet and jolly, smiling features, Hippos are extremely aggressive and do indeed claim up to 3000 lives per year – more than any other large animal.

The title of most dangerous animal of course goes to the mosquito. Not quite as dangerous as the urban myth which states that mosquitos can lay claim to almost half of all deaths EVER, they are still very, very dangerous. This is thanks to the diseases which they transmit to humans who have been bitten. Diseases which include Dengue Fever, Wild Nile Virus and most notably Malaria. Malaria infects around 250 million people each year worldwide and kills about one million, mostly children in Africa. About a fifth of those deaths can actually be attributed to counterfeit anti-malarial drugs.

Major research and development funding has been pumped into the field of malaria vaccination in recent years. One particular  financial partnership in this area has gained a lot of press – that between Bill Gates and British pharma corporation Glaxo Smithkline creators of the potential vaccine known as ‘RTS,S.’ Scientists state that full data from final-stage trials which include 15,000 children, are expected by the end of 2014. However, early results from the vaccine are not encouraging and expose the difficulties in creating a vaccine that offers full protection from a deadly disease such as malaria, which is caused by transmission of the P.falciparum parasite.

Never mind the baseless hysteria that often surrounds vaccines. As tools for public health, they are arguably the most effective. However, finding a vaccine for a disease like Malaria is proving quite troublesome indeed. Specifically because Malaria is caused not by bacteria but by a protozoan parasite. Protozoa are more complex organisms than bacteria or viruses with more complex structure and life cycles. Essentially, to develop an effective, universal vaccine for a parasite, a vaccine for each individual stage of the parasite’s life cycle would have to first be developed. At this point in time this has never been achieved.

Parasites, like bacteria, show a remarkable ability to develop resistance to vaccines, too. This is what seems to hampering the efforts of Bill Gates’ and GSK’s proposed vaccine. According to the New England Journal of Medicine, despite the RTS,S having an initial rate of protection peaking at 53%, after an average of merely eight months the level of protection had declined at an alarming rate. Sometimes as far as zero.

There is hope though. According to a GSK spokesperson,because the results were derived from a small, mid-stage trial, they did not “provide definitive answers about the duration of protection or how the vaccine candidate works in different malaria transmission settings.” Also, despite waning efficacy, the vaccine did show some clear benefits to a sizable portion of children tested.

Phillip Bejon, a researcher at the KEMRI-Wellcome Trust programme stated, “Many of the children (in Africa) will experience multiple episodes of clinical malaria infection, but overall we found that 65 cases of malaria were averted over the four-year period for every 100 children vaccinated. We now need to look at whether offering a vaccine booster can sustain efficacy for longer.”

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Read more: http://blogs.smithsonianmag.com/science/2011/07/14-not-so-fun-facts-about-mosquitoes/#ixzz2RITQ0KAm
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About the author: Conor Hughes works as a Marketing Executive at Life Science Recruitment

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