interaction with human peripheral blood leucocytes in vitro showed that h1n1 strains , a/ussr/90/77 and a/fiji/15899/83 , elicited significantly less ep ( as assessed by the rabbit pyrogen assay ) than two virulent clones , 7a and 64c , of the a/puerto rico/8/34-a/england/939/69 ( h3n2 ) reassortant virus system .
C0229664
peripheral blood
C0023516
leucocytes