For active immunisation of maternally derived antibody positive or negative calves from 3 weeks of age against BRSV and PI3, to reduce the mean titre and duration of excretion of both viruses.

Onset of immunity has been demonstrated at 10 days after a single vaccination. A statistical reduction of the amount of BRSV shed was also observed 5 days after vaccination in seronegative animals.

The duration of immunity is at least 9 weeks following a single dose.