Chickens were immunized with a synthetic peptide containing the influenza hemagglutinin (HA) epitope (i.e., YPYDVPDYA) conjugated to keyhole limpet hemocyanin. The first injection included complete Freund’s adjuvant; subsequent injections included incomplete Freund’s adjuvant. Eggs were collected after the fourth injection, and antibodies were purified from the yolks using a proprietary method that yields a purity of >90%.Antibodies were affinity-purified over a peptide column and then dialyzed against phosphate-buffered isotonic saline. Sodium azide was added and the antibodies were filter-sterilized (0.2 µm).