|Schultz Cherry, Stacey|
Submitted to: American Society for Virology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/30/1999
Publication Date: N/A
Technical Abstract: The hemagglutinin gene of the prototype human/avian influenza isolate A/HK/156/97 (H5N1) was cloned into VRP as previously described (Pushko et. al.; Virology 239:389). The system allows a single round of replication to express an introduced foreign protein, but progeny particles are not produced and the infection cannot spread. Since in ovo vaccination of poultry has become routine for some viruses, we tested the response of chickens vaccinated in ovo with HA-VRP. 18 day old embryos were vaccinated by inoculation in the allantois or embryo/yolk sac with 104 to 107 infectious units. Twenty-four hours later, the HA protein was found in numerous organs including thymus, spleen and intestines. Staining was distributed throughout the organs and also perivascularly. After hatch, some birds were re-vaccinated subcutaneously (sc) at 16 days of age. At 46 days of age the birds were challenged with a lethal dose of A/HK/156/97. Birds inoculated twice at the higher doses exhibited day of challenge reciprocal HI titers of 32-128, and were completely protected by the vaccine. Mice vaccinated with HA-VRP sc in the footpad were also protected against a lethal H5N1 virus challenge.