Integration of Spatial and Social Network Analysis in Vaccine Trials

This project will develop and test spatial analytical and social network analysis methods
for vaccine trials and disease transmission modeling. Existing methods limit the
extrapolation of results and are sometimes of questionable validity. This project builds
on earlier work by the investigators that developed theory and methods for incorporating
neighborhood-level variables into “ecological vaccine trials” (Ali et al., 2005, 2008; Emch
et al., 2006, 2007). In 1985, a community-based individually-randomized oral cholera
vaccine trial was conducted in Matlab, Bangladesh. This proposed study will reanalyze
the cholera vaccine trial data using new measures of social and environmental
connectivity developed with social network analysis software, a geographic information
system (GIS), and satellite remote sensing technologies. These new measures will help
determine: (1) how placebo incidence and protective efficacy (PE) vary within social
networks; (2) how placebo incidence and PE vary spatially by different environmental
contexts; and (3) how spatial, environmental, and social network information can be
used simultaneously to assess the effectiveness of vaccines and disease risk. We will
use four data sets, already collected by the investigators, including: (1) a large cholera
vaccine trial database, (2) a comprehensive longitudinal demographic database from
which the vaccine trial participants were selected, (3) an accurate household-level GIS
database, and (4) high resolution Quickbird satellite imagery. We will measure kinship
ties between all households using a complete network design as well as environmental
connectivity using satellite imagery and GIS techniques. These GIS and satellite
databases, in conjunction with the demographic, social network, and vaccine datasets,
will facilitate adding integrated spatial, environmental, and social components to this
vaccine evaluation study. Reanalyzing the Matlab oral cholera vaccine trial using a
spatial analytical framework and social and environmental connectivity measures can
give new insight into vaccine effectiveness evaluation and disease transmission
modeling. As a result, the theoretical and methodological issues addressed in this
project will have important implications for future vaccine trials.

Principal Investigator: Michael Emch

Other Investigators: Ali, Mohammed (International Vaccine Institute), Clemens, John (International Vaccine Institute)

Funding Source: NIH

Grant Number: R03 AI076748

Funding Period: 09/04/09-08/31/11