Scott C. Weaver, PhD
John Sealy Distinguished University Chair in Human Infections and Immunity
Director, Institute for Human Infections and Immunity
Scientific Director, Galveston National Laboratory
Professor, Departments of Pathology, and Microbiology & Immunology
Tel: (409) 266-6500
Fax: (409) 266-0610
E-mail: sweaver@utmb.edu
Campus Location: 6.200D Galveston National Laboratory
Mail Route: 0610
Research
Arboviral Ecology and Vaccine Development
Our research focuses on the genetics,
ecology, evolution and pathogenesis of arthropod-borne viruses
(arboviruses), virus-mosquito interactions and vaccine development. I
currently have 5 major research projects funded by NIH grants:
1. Venezuelan equine encephalitis virus (VEEV) is responsible for
several recent human and equine outbreaks in northern South America and
Mexico. We have shown that epidemic VEEV strains evolved very recently
from avirulent, enzootic viruses that circulate in sylvatic foci
involving rodent hosts and mosquito vectors. We are using ecological
studies, laboratory transmission experiments, and reverse genetic
approaches to study VEE emergence at the molecular, ecological and
geographic levels. The latter approach relies on satellite imagery to
map the locations of enzootic VEE viruses with emergence potential. This
project involves collaborations with scientists in Venezuela, Colombia
and Mexico, and at the USDA.
2. We use similar approaches to study retrospectively the emergence
of urban dengue viruses from zoonotic progenitors that use non-human
primate reservoir hosts and sylvatic mosquito vectors. This project
involves a collaboration with scientists at the Institut Pasteur in
Senegal. Susceptibility studies have demonstrated that emergence of
urban dengue was medicated by adaptation to peridomestic vectors, and
the genetic determinants of this adaptation are now being identified.
3. We are also examining the effect of deforestation on arboviral
diseases in the Amazon basin of Peru. Humans are now an important
component of Amazonian ecological systems, and we hypothesize that
anthropogenic disturbances alter the frequency of contact among
reservoir hosts, vectors and viruses, changing transmission cycles and
promoting epidemic emergence. Ecologic and laboratory studies are being
used to test 3 hypotheses: (1) deforestation alters the enzootic
transmission ecology, as vectors, reservoir hosts or viruses
differentially respond or adapt to anthropogenic changes; (2)
deforestation results in increased exposure of humans to arboviruses
through ecotone elongation and peridomestic virus circulation; (3)
arboviruses can adapt to introduced, peridomestic mosquito vectors and
human hosts to colonize tropical cities, with devastating public health
consequences. This project involves collaborations with mosquito and
mammal ecologists at the University of Florida, Texas Tech University
and the U.S. Naval Medical Research Center Detachment in Peru.
4. Because the vectors of most neotropical arboviruses belong to a
subgenus [Culex (Melanoconion)] with poorly developed taxonomy and
systematics, we are studying this group using molecular phylogenetics to
develop a natural classification and genetic diagnostic tools. This
project is a collaboration with Dr. Juan Carlos Navarro the Central
University of Venezuela.
5. We are also developing new chimeric vaccines against VEEV, as
well as eastern and western equine encephalitis viruses. Based on the
Sindbis virus backbone and encephalitic alphavirus structural proteins,
these chimeric viruses are useful as diagnostic reagents to improve
laboratory safety. This project involves collaborations with Drs. Ilya
Frolov, Slobodan Paessler and Judy Aronson at UTMB, Hans Heider at U. T.
San Antonio, and William Klimstra and Kate Ryman at the LSU Medical
Center.
Publications