Samuel Bosomprah BSc MSc

Research Degree Student

I had BSc in Statistics from the University of Ghana, Legon in 2000. I joined the London School in 2005 and obtained MSc in Medical Statistics in 2006, before that I worked for 4 years in Ministry of Health in Ghana. I am now studying PhD in Medical Statistics related to malaria vaccine studies, affiliated to Department of Infectious Disease Epidemiology.

Affiliation

Teaching

I am currently a Lecturer in Biostatistics in the University of Ghana School of Public Health, Ghana. I teach the Advanced Statistical Methods in Clinical Trials module of the MSc in Clinical Trial course.

Research

The PhD is sponsored by the EMVDA and AMANET. The work is in three parts. Firstly, analysis of cohort studies to evaluate potential vaccine candidate antigens for a malaria blood-stage vaccine. This part was implemented under the Afro-Immuno Assay (AIA) project. The first phase of the AIA was initiated to standardize immunological assays in order to validate promising malaria vaccine candidate antigens and to enhance quality assured laboratory capacity. The antigens initially considered were blood-stage antigens AMA1, GLURP, MSP119 and MSP3. In these studies the age range varies and the method of detecting malaria cases varies thus raising concern over the design. Therefore, phase 2 of the AIA was initiated to consider new antigens (MSP1-Block 2 hybrid and AS202.11) designed to incorporate antigenic diversity and GLURP R2 and to standardise the epidemiological and statistical methods to compare results from Ghana and Burkina Faso. The MSP1-Block 2 hybrid is a fusion of different alleles of MSP1 Block 2, which is expected to elicit broader antibody response. The AS202.11 is a novel antigen derived using the newly available full genome sequence of P. falciparum. This was one of 70 peptides that were examined in a cohort study in Kenya, and was one of only two peptides which showed significant association with malaria incidence in two different cohorts (Agak et al., 2008). Two of these antigens, GLURP and MSP3, have been formulated into a recombinant protein in the vaccine candidate GMZ2, this vaccine has undergone phase 1 trials in adults and children is now progressing to a Phase 2b efficacy trial. The second part of this project is to investigate aspects of the design of this efficacy trial (planning for adequate power in context of declining malaria incidence). Malaria transmission is decreasing steadily all over sub-Saharan African. As a result, malaria incidence is unpredictable in several settings, which have implication on vaccine efficacy trials. The third part is to investigate the use of age-stratified cross-sectional data on malaria antibody prevalence to estimate changes in transmission intensity.  

In particular, I am interested in:

a) Summarising existing evidence from immuno-epidemiological cohort studies in order to provide insight into the vaccine potential of commonly studied asexual blood stage antigens (MSP1, MSP3 and GLURP);

b) reviewing the methodologies that have been used and the potential sources of bias in the estimation of associations in these studies;

c) Analysing data from the AIA phase 1 studies (Ghana and Burkina Faso)

d) Estimating protective effect of naturally acquired antibody responses to GLURP-R2 and two new synthetic antigens, MSP1-BL2 hybrid and AS202.11, on incidence of clinical malaria from cohort studies conducted in collaboration with AMANET;

e) Planning a strategy for recruitment in efficacy trials in a situation where malaria incidence is unpredictable

f) Estimating changes in transmission intensity in the recent past using the concept of super-infection mathematical model.

Research areas

  • Child health
  • Clinical trials

Disciplines

  • Epidemiology
  • Immunoepidemiology
  • Statistics

Disease and Health Conditions

  • Malaria

Other interests

  • Antibody Response
  • Immunogenicity
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