Langat virus (LGTV) is a virus of the genus Flavivirus. The virus was first isolated in Malaysia in 1956 from a hard tick of the Ixodes genus.[1] This virus is antigenically related to Omsk hemorrhagic fever virus, Kyasanur forest disease virus, Alkhurma virus, Louping ill virus and other viruses of the tick-borne encephalitis virus (TBEV) complex. The Langat virus does not pose a significant epidemiological threat in comparison with TBEV. There are no known cases of human diseases associated with LGTV.[2] The Malaysian strain (LGT strain TP21, also known as the Yelantsev virus) is naturally attenuated and induces neutralizing antibodies to tick-borne encephalitis virus (TBEV) and protection against other TBEV complex viruses in animals.[3]
LGTV-based vaccine
In the 1970s a live attenuate LGTV-based vaccine against tick-borne encephalitis was made. At the same time, another vaccine was tested, but the group vaccinated with the LGTV-based vaccine had the lowest level of developing infection decease.[4] However, there were two major problems: the relatively high rate of incidents of encephalitis (1:10,000) and lack of absolute protection from infection in endemic regions.[citation needed]
^Shapoval AN; Kamalov II; Denisova EIu; Sokolova ED; Luzin PM; Shamarina AG; Gusmanova AG; Pinaeva NI (1989). "Study of the distant consequences of immunizing people with a live vaccine against tick-borne encephalitis". Tr Inst Im Pastera (in Russian). 65: 133–5. PMID2629181.