title: A live vaccine against tick-borne encephalitis: integrated studies. I. Basic properties and behaviour of the E5 "14" Clone (Langat virus).
abstract: The course of plaque segregation from the Langat E5 strain of the E5 "14" clone is described. The virus, displaying an ic+ sc s plus or minus t e u s character, reproduced at 35 and 37, but not at 39 degree C. In subcutaneously (sc) inoculated monkeys, viraemia lasted for 2--4 days without detectable central nervous system (CNS) involvement. In sc inoculated 8--10 g mice, the infection was manifested only by a transient trace viraemia, but caused a marked resistance against challenge with virulent tick-borne encephalitis (TE) viruses, protection indices being 5.7--6.7. Pathogenetic investigations in challenged, live virus-immunized mice showed no signs of a marked productive infection except of a booster effect.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral; D001103:Arboviruses; D003588:Cytopathogenic Effect, Viral; D004669:Encephalitis Viruses, Tick-Borne / Q000276:immunology / Q000302:isolation & purification / Q000472:pathogenicity; D004675:Encephalitis, Tick-Borne / Q000517:prevention & control*; D000882:Haplorhini; D051379:Mice; D013696:Temperature; D014613:Vaccines, Attenuated; D010948:Viral Plaque Assay; D014765:Viral Vaccines; D014779:Virus Replication
chemical_list: D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D014765:Viral Vaccines