Effect of aerosol challenge on a population of free lung cells in parenterally immunised calves.

There is concern that parenteral respiratory vaccines may potentiate lung disease rather than protect against it. In vivo indicators of inflammation in calves were assessed to determine if vaccine-mediated inflammation occurs in the lung following aerosol challenge of parenterally immunised subjects. Preliminary results using a simple protein antigen suggest that changes in the free cell populations of the lung are likely to be a more sensitive indicator of immune-mediated inflammation than clinical parameters or peripheral changes in serum complement.