Effect of subcutaneous pox vaccination of young chicks on immune responses and weight gains

Two fowl pox and two pigeon pox vaccines were administered subcutaneously in the dorsum of the neck of specific-pathogen-free (SPAFAS) chicks at day of hatch in separate studies. Treatment levels used were 1:2, 1:10, or 1:50 dilution of the recommended wing web dose. Both pigeon pox vaccines and one fowl pox vaccine depressed body weight gains significantly by day 14. Mean body weight gains of female chicks were less affected by pigeon pox vaccines than by fowl pox vaccines. The mean hemagglutination-inhibition (HI) antibody titer to Newcastle disease virus (NDV) of chicks given one pigeon pox vaccine at the 1:2 dilution was significantly lower (P less than .01) than titers of sham-treated controls. The number of immunoglobulin-M (IgM) secreting cells in the spleen was significantly less (P less than .05) at day 14 in all pox vaccinated chicks when compared to sham-treated controls.