comparative h.i . and in ovo neutralization tests with the first and second series of variants revealed that the three variants , fd/s , gf/s , and hg/s , of the second series , failed to react with pr8-s antisera and produced significantly smaller amounts of antibody which reacted with pr8-s , the variants of the first series , and the first variant ( d/s ) of the second series .
C0020960
antisera
C0003241
antibody