A vaccine for malaria, which was created by scientists at The University of Edinburgh, has been further developed after research discovered a key protein in the blood of African children, who were naturally exposed to the infected mosquitoes that cause the disease.
Dr David Cavanagh, Senior Lecturer for The Institute of Immunology and Infection Research at The University of Edinburgh told The Journal: “We identified this protein, which is found on the surface of blood stage malaria parasites, as a target of antibody responses in African children naturally exposed to malaria by their exposure to infected mosquitoes.
"Importantly, we observed that the children who had antibodies in their blood to this protein were less likely to become ill with malaria than children who lacked these specific antibodies. Antibodies to other parasite proteins did not correlate with this protection.
“Our vaccine targets the malaria parasite form that emerges from the liver, and which then rapidly infects red blood cells, causing the characteristic fever and death in infected children. The blood stage of the parasite is the stage of the parasite life cycle which is responsible for the disease we know as malaria.”
It is hoped that the new vaccine can be combined with the existing RTS,S vaccine in order to combat the disease’s ability to create new strains of itself, each having to be dealt with by the human immune system differently. The study has already proved successful in preliminary trials on animals and has subsequently applied for trials to be carried out on humans.
Dr Cavanagh added: “Most scientists would probably agree that any highly effective vaccine against malaria will need to get above the 50 per cent effectiveness of RTS,S has at the moment. We'd like to think that our blood-stage vaccine could complement RTS,S or a similar liver stage vaccine, and get us close to the World Health Organisation (WHO) target of an 80 per cent effective vaccine by 2025.”
However, the vaccine could take up to another ten years to be developed with human trials being expensive and funding difficult to attain. Dr Cavanagh said: “RTS,S has been in development for over 20 years, so we are at the beginning of a very long road. It can take 10 years or more for a prototype vaccine to reach the people who need it."
Malaria is spread by mosquito bites and affects 225 million people, causing an estimated 781,000 deaths in 2009 according to The World Health Organisation (WHO).
Dr Cavanagh stressed that the vaccine would “need to be free, especially in Africa where the people who need it are living on one or two dollars per day. That requires BIG money from governments.”
The full study has been published in the journal PLoS One.