West Nile Virus first reached the United States in 1999. Since that time, it has become the leading vector-borne cause of viral encephalitis in the U.S.
By 2010, the number of adults who had been infected with West Nile Virus in the U.S. was estimated to be 3 million, with 13, 000 cases of West Nile neuroinvasive disease – almost half of which occurred in adults over 60 years of age.
Severe illness has been seen in the U.S. and may cause hepatitis, meningitis, and encephalitis leading to paralysis, coma and death. Importantly, the second largest outbreak of West Nile Virus occurred in the U.S. in 2012 with the Centers for Disease Control and Prevention reporting 5,674 cases and 286 deaths. This is the highest death rate attributed to the virus since the first case occurred in the United States in 1999.
At present, a licensed vaccine is not available for the prevention of disease in humans, and mosquito eradication has been the only strategy available to control West Nile Virus. That is about to change.
Recently, the National Institutes of Health have developed a live-attenuated West Nile Virus vaccine using recombinant DNA technology. This vaccine has been studied in healthy adults ages 18-50 and has been found to be well tolerated, immunogenic, and most importantly, safe. Currently, the Vaccine Testing Center here at the University of Vermont Medical Center and the University of Vermont, in conjunction with Johns Hopkins Bloomberg School of Public Health and the National Institutes of Health, is starting a West Nile Virus Vaccine Study to test the efficacy of the vaccine in healthy adults ages 50-65.
This is a very exciting time for us. An effective West Nile Vaccine is greatly needed, and as the disease is endemic in Vermont, this is the perfect population in which to test the vaccine’s effectiveness.
If you are interested in participating in the study, please contact the Vaccine Testing Center at 656-0013 or email: firstname.lastname@example.org.
Kristen Pierce, MD, is an Infectious Disease Specialist at the University of Vermont Medical Center and an Assistant Professor at the University of Vermont College of Medicine.