ten out of 11 sheep , which were followed from 3 months after experimental inoculation to 16-21 months ( 5 sheep ) or 3 years ( 6 sheep ) after inoculation , developed transient late virus-specific cell-mediated responses with intermittent virus isolation from peripheral blood leucocytes ( pbl ) over the period of study .
C0229664
peripheral blood
C0023516
leucocytes