Thailand on Wednesday decided against vaccinating local poultry against the potentially lethal bird flu virus, ending an emotional debate between the country’s vast chicken-exporting industry and enthusiasts of the traditional sport of cock-fighting.

Thai agricultural and public health officials concluded that inoculating birds - as demanded by breeders of the valuable fighting cocks - could jeopardise human health, since vaccinated fowl would not display symptoms but might nevertheless be carrying the bird flu virus and transmit it to humans.