Virus neutralization titers in live vaccine groups.

A) VN titers against TAT strain for the TAT- and PTA-live vaccinated fish increased markedly from 4 to 8 weeks post vaccination (wpv). B) VN titer against the PTA strain was also examined and showed that the homologous titer for the PTA vaccinated fish were equal to their cross-reactivity to the TAT variant. C) VN titers at 8 and 17 weeks post challenge (wpc) were examined and while the TAT-live show no increase from time of challenge (A) there is an increase for the PTA-live group. Control fish cohabiting with the vaccinated fish also show an increase. By 17 wpc there is a marked increase in all groups. N = 12; ±SEM.