Abstract: Inactivated antigens have only been used in avian medicine in parenterally administered vaccines. The only mucosally administered vaccines have been live, modified live, or attenuated vaccines. However, live vaccines have several disadvantages, including the risk of causing disease. Disclosed embodiments concern a composition comprising inactivated bacterial and/or viral antigens that is formulated for mucosal administration to an avian, and a method of using the composition. In certain embodiments, the composition comprises inactivated Clostridium perfringens type A antigens, and/or Salmonella spp. antigens, such as antigens from Salmonella kentucky, Salmonella typhimurium, and/or Salmonella enteriditis, or E. coli antigens. The composition may comprise a polyacrylic acid adjuvant. The composition may be administered to an avian in ovo, during the first 14 days after hatching, or after the first 14 days.