Philip Bejon: Malaria in Kenya
Understanding the variation of malaria risk between houses, villages or region, and how malaria is transmitted in and around that variability helps develop better malaria control programmes and use their resources more wisely. Since malaria control tools are becoming less effective with time, progress in vaccine design is essential.
Q: Can you tell us a little about your research interests?
Philip Bejon: I am the director of the KEMRI-Wellcome Trust which is a major overseas programme in Kenya. That job involves being interested in the research that a large group of colleague do, and their research interests are based around quite a range of different infections and a range of different specialties - from molecular work, immunology work, clinical work, through to social science and work on health systems. I am interested in that, though it is not my own research; my personal research is based on vaccine trials with a particular interest in malaria vaccines trials and on the spatial epidemiology of malaria.
Q: Why are you particularly interested in studying malaria?
PB: Malaria is a very important thing to study because it kills a lot of people. We don't know exactly how many people it kills; the estimates that are available are in the range of half a million deaths per year, the majority of those in Africa.
Q: How does the understanding of spatial epidemiology contributes towards research in malaria?
PB: There are a number of control tools that can be used to try and reduce the deaths from malaria. If we understand what the spatial epidemiology of malaria is, we can use them in cleverer ways.
There are two important questions I am trying to deal with in terms of the spatial epidemiology of malaria. One is: what is the variation? Are we able to identify particular villages that are at high risk compared with other villages? Or can we identify particular houses within villages that are at higher risks compared with other houses? Understanding how that works and how it changes from year to year could help malaria control programmes use their resources more wisely.
The second question is understanding how malaria is transmitted in and around that variability. For instance, if you have malaria today, having slept in a particular homestead, then where did that malaria come from? Is it most likely from the high risk homestead next door, or the high risk village next door, or even from another region entirely? If we can put the answers from these two questions together, we can construct a control strategy that could interrupt the network of transmission and make a really big difference.
Q: What are the most important areas of research that have developed in the last 5-10 years?
PB: Here I would like to talk about my other interests into malaria vaccines. Over the 5-10 years up to today there has been quite a lot of progress actually. The GSK [GlaxoSmithKline] vaccine which is called RTS,S has been through several phases of testing. Based on the data that has come out of that, it is now going through an application for a products license which would make a vaccine that could be sold and given in routine vaccination programmes.
Our research programme played a leading role in many of those stages of testing. We are very proud of having played that role, but to be clear, the efficacy of that vaccine is not high: it is in the range of 20-30% and goes down to 0% by the time 3 or 4 years have passed. So, clearly, we need to do better.
Q: Why does your research matter and why should we fund it?
PB: I have mentioned the deaths that occur because of malaria and I have mentioned that there are malaria control tools available; to be specific ,there are bed nets and anti-malarial drugs, and also spraying with insecticides. Those measures aren’t perfect, even today, and in the future they are going to become even less perfect because the mosquitos are becoming resistant to insecticides and the malaria parasites are becoming resistant to drugs. We need something else and for many infectious diseases, vaccines have been a very successful and cost-effective way of controlling them.
Q: How does your research fit into translational medicine within the department?
PB: There are two main areas of collaboration. One is with the Jenner Institute - I have mentioned the GSK vaccine. We have also collaborated with the Jenner Institute in testing a number of the Jenner’s malaria vaccines products which are at a slightly earlier stage of testing, but we have seen some very encouraging signs of effectiveness of those vaccines when we have tested them.
I mentioned needing to understand how parasites move around from homestead to homestead, or from region to region. We collaborate with Dominic Kwiatkowski’s group in the Wellcome Trust Centre for Human Genetics: that work is based around genetic typing of the parasites. Being able to see the genetic type and compare that genetic type with the parasites from the homestead next door, or from the villages next door, gives us a lot of information about how parasites are moving around, and that is quite critical for our agenda in terms of malaria control tactics.
This interview was recorded in September 2015.