Prof Simon J. Draper, University of Oxford, Professor of Vaccinology and Translational Medicine, Wellcome Trust Senior Fellow
The dawn of a new era in malaria prevention is coming soon, as scientists work on developing and trialling malaria vaccines. Here’s what’s happening now.
Hopes are high that malaria could be defeated soon, with malaria vaccines in clinical trials now.
“We need effective vaccines as soon as possible,” says Simon Draper, the Professor of Vaccinology and Translational Medicine who heads the Blood-Stage Malaria Vaccine Group at the Jenner Institute, University of Oxford. “In the year 2000, malaria was claiming about a million lives a year globally. By 2018 bed nets, insecticides and anti-malarial drugs had reduced that to around 450,000, but that improvement seems to be stalling.”
Apart from the human toll, malaria control is costing the world US$ 2-3 billion a year.
“The battle to develop a malaria vaccine is at a very exciting stage,” says Simon. “Trials of vaccines are happening now, and more start soon.”
The nature of malaria makes vaccine development difficult. Simon explains: “When an infected Anopheles mosquito feeds on a human, it injects the Plasmodium parasite, which stays in the liver for a week before bursting out into the bloodstream, at which point symptoms of malaria appear. When another mosquito feeds on an infected human, the Plasmodium is passed on.
“We now have methods to induce the production of antibodies to stop the Plasmodium in its tracks at three points: in the blood, the liver, and in the mosquito.”
A different vaccine is required for each, but vaccines developed at the institute are being trialled now. Phase I/II trials of a vaccine that targets the liver are already underway in both Oxford and Africa; a vaccine targeting the blood is undergoing Phase I trials in Africa, and a trial targeting the mosquito-stage starts soon.
Oxford’s unique approach
The Jenner Institute is the only place in the world that is working on all three approaches at once. “Our long-term goal is to develop a vaccine that will stop the Plasmodium in all three sites at the same time,” says Simon, who is working on the blood-stage vaccine. His colleagues, Professors Adrian Hill and Sumi Biswas, are working on the liver and mosquito stages.
“Everyone is keen to produce safe and cost-effective vaccines as soon as we can, but careful, staged trials are essential to determine safety, dosages, and whether the vaccine works effectively,” says Simon.
“We will not know for sure whether our vaccines reduce episodes of malaria until the trials in Africa are completed, but we are collaborating with academics, small biotech companies and big pharmaceutical companies, with the ultimate aim of getting safe, effective vaccines licensed as soon as possible.”
By Linda Whitney