Intake and stability of a rabies vaccine.

The intake and stability of rabies vaccine baits were studied over a two week period under field conditions. High intake of vaccine baits was observed in the spring and autumn. In the spring, the intake of vaccine baits lasted almost two weeks while in the autumn vaccine baits were consumed over the first days following distribution. Differences in bait stability were observed after exposure to ambient temperatures. Baits were more stable in a forest environment than on the edge of a forest. Deformation and disintegration of bait casing occurred with some baits at the beginning of trial. Rainy weather was probably detrimental to bait casing stability. Vaccine titres were stable for nine days in the forest and six days on the edge of a forest in the spring, while results of the study make it possible to predict that vaccine titres may have decreased rapidly in the autumn. Laboratory results on bait stability were different from those obtained in the field.