A live vaccine against tick-borne encephalitis: integrated studies. I. Basic properties and behaviour of the E5 "14" Clone (Langat virus)
Acta Virologica 19(3): 209-218
ISSN/ISBN: 0001-723X PMID: 239576 Accession: 039070503
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.