A Phase 1, Open Label, Safety Study of HBV-002 (West Nile Recombinant Subunit Vaccine) in Healthy Adults.

Since its introduction in 1999, West Nile virus (WNV) has become endemic to the United States and many other countries around the world and is a leading cause of viral encephalitis each year. Despite the need, there are no licensed vaccines or therapies to address West Nile virus disease. The HBV-002 vaccine, which consists of the recombinant WNV envelope subunit protein (WN-80E) and Alhydrogel '85' (Croda Pharma, Princeton, NJ), was tested in an open-label, dose-escalation Phase 1 clinical trial (NCT00707642) alongside a WN-80E cohort without adjuvant. HBV-002 was found to be generally safe and well-tolerated, with mild, short-lived adverse events (AEs; 23 of 25 participants experienced Grade 1 AEs, and one participant experienced a Grade 2 AE that was determined not to be related to the vaccine). HBV-002 was immunogenic in all participants who received the adjuvanted HBV-002, as evidenced by virus-neutralizing antibody titers post-dose 3. The magnitude of the immune responses was dose-dependent and declined over time. Overall, these results reveal the potential of the vaccine candidate but indicate the need to further optimize the vaccine formulation or schedule to ensure long-lasting protection.