The present invention relates to an improved vaccine against Coccidiosis in poultry. The vaccine comprises live Eimeria oocysts in a composition with relatively high viscosity because of the inclusion of between 0.3 and 1.5% w/v Xanthan gum. Upon spray vaccination the new vaccine forms beads that are 5 quickly ingested by the birds and which provide a rapid vaccine take, resulting in a quick and effective improvement of the signs of Coccidiosis upon challenge infection. Also the invention relates to a method for the heat sterilisation of a composition comprising Xanthan gum; by the inclusion of a concentration of a metal salt, an irreversible and dramatic reduction in viscosity can be largely prevented.