RTS,S Malaria Vaccine not Found to be Modified by Spatial Location or Ecological Factors During a Phase III Randomized, Controlled Trial in Lilongwe, Malawi

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  • February 26, 2019
Creator
  • Bell, Griffin
    • Affiliation: Gillings School of Global Public Health, Department of Biostatistics
Abstract
  • RTS,S was the first vaccine for Malaria approved for use by the European Medicines Agency and it is set to be administered to 360,000 children in Malawi, Ghana, and Kenya as part of a pilot implementation program in fall 2018. The efficacy of RTS,S was variable, possibly due to differences in transmission intensity, between the 11 sites and 7 countries participating in the 2009-2014 phase III trials. However, a within-site analysis examining environmental factors related to transmission intensity has yet to be conducted. We used data from the phase III trial of RTS,S, which enrolled 1,578 infants (6-12 weeks) and children (5-17 months) living in the Lilongwe District in Central Malawi and followed them for up to 4 years. A global positioning system survey and an ecological questionnaire were used to collect household locations and characteristics in order to investigate whether spatial location or household ecological factors were associated with the efficacy of RTS,S. We used negative binomial regression models to assess the effect of the vaccine on number of malaria episodes.Using data from 1189 (75.3%) of the phase III participants, we found that the location-specific malaria incidence varied over the study region from .072 to 2.11 estimated episodes per year. We found no evidence supporting the hypothesis that the efficacy of the RTS,S vaccine varied over the Lilongwe study region. We also found that malaria incidence was associated with grass roofs, certain window types, proximity to a waterway and low population density. However, we found no evidence supporting the hypothesis that these ecological variables impacted the efficacy of RTS,S.Our results suggest that transmission intensity did not play a role in the intra-site efficacy of RTS,S in Lilongwe, Malawi during the phase III trial.
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  • In Copyright
Note
  • Funding: Class of 1938 Fellowship
Advisor
  • Loop, Matthew
Degree
  • Bachelor of Science in Public Health
Academic concentration
  • Biostatistics
Honors level
  • Honors
Degree granting institution
  • University of North Carolina at Chapel Hill
Graduation year
  • 2018
Language
  • English

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