Evaluating the Safety and Immunogenicity of a Live Attenuated West Nile Virus Vaccine for West Nile Encephalitis in Adults 50 to 65 Years of Age

West Nile Virus Clinical Trial

Official title: Phase 1 Study of the Safety and Immunogenicity of a 2-Dose Regimen of West Nile/Dengue 4-3´Δ30 Chimeric Virus Vaccine (WN/DEN4Δ30), a Live Attenuated Vaccine for West Nile Encephalitis, in Flavivirus-naïve Adults 50-65 Years of Age

Status Completed

Clinical Trial Summary

West Nile virus (WNV) is considered an emerging virus in the United States, and infection can lead to severe illness in older adults. This study will evaluate the safety of and immune response to a live West Nile virus vaccine (WN/DEN4Δ30) for the prevention of West Nile encephalitis in adults 50 to 65 years old.

Clinical Trial Description

WNV is the leading vector-borne cause of viral encephalitis in the United States. Severe illness is most common in older adults, and in this population, the virus can cause hepatitis, meningitis, and encephalitis leading to paralysis, coma, and death. WNV illness is a public health issue and is an emerging disease in the United States. This study will evaluate the safety and immunogenicity of a live attenuated West Nile/dengue chimeric virus vaccine (WN/DEN4Δ30) for the prevention of West Nile encephalitis in adults 50 to 65 years old.

This study will enroll healthy adults, 50 to 65 years old, who have no history of previous flavivirus infection. Participants will be randomly assigned to receive the WN/DEN4Δ30 vaccine or placebo vaccine at study entry (Day 0). At the entry visit, participants will undergo a medical history review, physical examination, blood collection, and vital sign measurements; female participants will also take a pregnancy test. Participants will then receive their assigned vaccine, and they will remain in the clinic for 30 minutes after the vaccination for monitoring. Participants will record their temperature and symptoms 3 times a day for 16 days after each vaccination. Additional study visits will occur on Days 3, 6, 8, 10, 12, 14, 16, 21, 28, 56, 90, and 150. These visits may include the same study procedures that occurred at the entry visit. At a study visit on Day 180, participants will receive another dose of their assigned vaccine. Additional study visits will occur on Days 183, 186, 188, 190, 192, 194, 196, 201, 208, 236, 270, and 360. All study procedures after the second vaccination will be the same that occurred after the first vaccination. ;

Related Conditions & MeSH terms

• Encephalitis
• West Nile Virus

• NCT number: NCT02186626
• Study type: Interventional
• Source: National Institute of Allergy and Infectious Diseases (NIAID)
• Status: Completed
• Phase: Phase 1
• Start date: February 2014
• Completion date: July 2016