A Phase 1, Open-Label Assessment of a Dengue Virus-1 Live Virus Human Challenge Strain

Abstract

Background: Dengue human infection models (DHIM) have been used as a safe means to test the viability of prophylaxis and therapeutics.

Methods: A phase 1 study of 12 healthy adult volunteers using a challenge virus, DENV-1-LVHC strain 45AZ5, was performed. A dose escalating design was used to determine the safety and performance profile of the challenge virus. Subjects were evaluated extensively until 28 days and then out to 6 months.

Results: Twelve subjects received the challenge virus: 6 with 0.5 mL of 6.5 × 103 plaque-forming units (PFU)/mL (low-dose group) and 6 with 0.5 mL of 6.5 × 104 PFU/mL (mid-dose group). All except 1 in the low-dose group developed detectable viremia. For all subjects the mean incubation period was 5.9 days (range 5-9 days) and mean time of viremia was 6.8 days (range 3-9 days). Mean peak for all subjects was 1.6 × 107 genome equivalents (GE)/mL (range 4.6 × 103 to 5 × 107 GE/mL). There were no serious adverse events or long-term safety signals noted.

Conclusions: We conclude that DENV-1-LVHC was well-tolerated, resulted in an uncomplicated dengue illness, and may be a suitable DHIM for therapeutic and prophylactic product testing.

Clinical trials registration: NCT02372175.

Keywords: dengue human infection model (DHIM); dengue virus; illness.