In vitro antiviral activity of adenosine analog NITD008 against tick-borne flaviviruses

There are currently no antiviral therapies available for the tick-borne flaviviruses associated with hemorrhagic fevers: Kyasanur Forest disease virus (KFDV), both classical and the Alkhurma hemorrhagic fever virus (AHFV) subtype, and Omsk hemorrhagic fever virus (OHFV). In this brief study, we describe the in vitro antiviral activity of adenosine analog NITD008 against KFDV, AHFV, OHFV, as well as Tick-borne Encephalitis virus (TBEV). Alongside the well-established activity of NITD008 against mosquito-borne flaviviruses, our results have demonstrated the feasibility of identifying nucleoside analog inhibitors that have pan-flavivirus activity. •Adenosine analog NITD008 shows in vitro antiviral activity against highly-pathogenic tick-borne flaviviruses.•NITD008 had the lowest potency against AHFV and the highest potency against OHFV and TBEV.•Treatment of flavivirus infected cells with 11 μM of NITD008 reduced tick-borne flavivirus titers by 102.5–105.5-fold.