Interferon induction in piglets with polyinosinic:polycytidylic acid complexed with poly-L-lysine and carboxymethylcellulose.

When newborn piglets were inoculated intravenously with 1.0, 0.5 or 0.25 mg kg-1 of polyinosinic:polycytidylic acid (poly I:C) complexed with poly-L-lysine and carboxymethylcellulose (poly ICLC), the highest serum interferon levels and the lowest white blood cell counts were found in response to a dose of 0.5 mg kg-1. Similar responses were observed in weaned piglets inoculated with 0.25 mg kg-1 of poly ICLC. Poly ICLC was a more effective interferon inducer than poly I:C, particularly in newborn piglets.