I am a Medical Research Council Fellow who specialises in the use of statistical and mathematical models to assist in developing control strategies for vaccine-preventable diseases. In recent years my focus has been on polio eradication and research questions relevant to endemic countries and countries at risk of an outbreak. This research has been in collaboration with the WHO Polio Eradication Initiative, and it has been a valuable opportunity to contribute to a global health priority. Models are extremely useful tools as they can capture the processes that form the data, and allow us to answer research questions that can be used to inform policy decisions. I am particularly interested in statistical methods that account for unobserved processes and typically these are considered within a Bayesian framework.
I teach on the MSc Epidemiology and BSc Biology courses at Imperial, and also teach on the Infectious Disease Short Course. I frequently supervise students for their dissertations; please get in touch if you are interested in doing a project with me.
Endemic polio countries, such as Afghanistan and Pakistan, face very specific problems where vaccinating every child is critically important. In a paper published in the Lancet, I estimated the vaccine efficacy of three commonly used vaccines (trivalent bivalent and monovalent oral polio vaccines) and changes in population immunity from 2001-2011. Assistance with the eradication efforts in Pakistan are continuing, and include development of a methodology to estimate vaccination coverage from surveillance data and understanding the extent of poliovirus infection.
Countries in Africa have experienced a series of outbreaks as a result of international spread of poliomyelitis. I developed and parameterised a statistical model to predict the timing, location and size of these outbreaks, to be used to assist vaccination planning. This research was published in PLOS medicine, and research is continuing in collaboration with WHO.
I am also very interested in understanding the effectiveness of routine immunisation in protecting children from disease. Initial research has explored the impact of transport networks in Africa on measles immunisation coverage. Further work will explore how models can be used to inform policy on where to invest in routine immunisation to reduce disease burden.
Much of my research into poliomyelitis has been relayed to policy makers, to assist with vaccination planning and assess whether changes in policy have resulted in a change in the epidemiological situation. My research has been presented as part of the GPEI Strategic Plan (2010-2012), has been presented at the GPEI Independent Monitoring Board and I frequently provide advice to stakeholders.
In July 2012 I was part of an independent team that visited Afghanistan to identify why the number of cases of poliomyelitis increased in 2011 and what district-level policies can be made to reduce the case load.
Science and society
It is very important to me to ensure that science is relevant to modern society and that science is taught well in schools. I have been involved with several projects, including “Illustrating Science”, funded by the Wellcome Trust, and I am a STEM ambassador. I also helped screen the film Contagion and discuss the film with local schools, in collaboration with Clapham Picturehouse. Students have also carried out research placements with me as part of the Nuffield Foundation.
Prior to Imperial
From 2007-2009 I was a post-doc at the University of Glasgow, within the Boyd Orr Centre. I have also worked at the Veterinary Laboratories Agency (2006-2007), where I worked on the epidemiology and control of Salmonella in pigs. During my PhD (Warwick) I used mathematical models to determine suitable strategies for control ofCorynebacterium pseudotuberculosis infection, which causes caseous lymphadenitis in sheep. Prior to my PhD I published work on determining risk factors for mastitis in dairy cows and pre-weaning mortality in pigs.
et al., 2015, Impact of inactivated poliovirus vaccine on mucosal immunity: implications for the polio eradication endgame, Expert Review of Vaccines, Vol:14, ISSN:1476-0584, Pages:1113-1123
et al., 2015, New Routes to Phylogeography: A Bayesian Structured Coalescent Approximation, Plos Genetics, Vol:11, ISSN:1553-7404
et al., 2014, Transport networks and inequities in vaccination: remoteness shapes measles vaccine coverage and prospects for elimination across Africa, Epidemiology and Infection, Vol:143, ISSN:1469-4409, Pages:1457-1466
et al., 2012, The effect of mass immunisation campaigns and new oral poliovirus vaccines on the incidence of poliomyelitis in Pakistan and Afghanistan, 2001-11: a retrospective analysis, The Lancet, Vol:380, ISSN:0140-6736, Pages:491-498
et al., 2011, A Statistical Model of the International Spread of Wild Poliovirus in Africa Used to Predict and Prevent Outbreaks, Plos Medicine, Vol:8, ISSN:1549-1676