When is the risk of fowl pox transmission highest on deep-litter brown egg farms, and when is the ideal age to vaccinate?

Fowl pox, caused by an avipoxvirus, manifests in two clinical forms: cutaneous (dry pox with scabs on wattles and comb) and diphtheritic (wet pox causing asphyxiation due to lesions in the trachea). Transmission risk peaks during the warm, humid summer and monsoon months (May to September) when blood-sucking mosquito vectors (primarily Culex species) multiply rapidly. Flocks housed on deep litter or free-range yards are at extremely high risk. To establish permanent immunity, replacement brown pullets must be vaccinated between 8 and 12 weeks of age, utilizing the wing-web double-needle stab method. Farmers must check for vaccine "take" (swelling or scab at the injection site) 7 to 10 days post-vaccination to ensure successful immunization. Pathology and vaccine manuals are indexed in the Poultry Encyclopedia, fowl pox vaccines and double-needle wing web applicators are sold on Poultry Plaza, daily bird rates are on Poultry Rates, and vaccinated layer stocks are listed on Murghi Mandi.