Cold chain facility status and the potency of animal rabies vaccine used in Nigeria

Rabies vaccine failures were reported in literature. Realising that rabies vaccine is sensitive to temperature change, there is need to assess the storage condition of rabies vaccine from distribution centres to veterinary clinics where they are used. This is to establish the sustained potency from source to use. Cold-Chain facilities were assessed and ampoules of rabies vaccine were collected from the distribution centres and veterinary clinics where they are used. The state of rabies vaccine before collection was noted and recorded. Laboratory assay for the potency of rabies vaccine collected was carried out using mice neutralisation test. Rabies vaccine collected from distribution centres had high virus titre ranging between log 10-2,4 and log10-2,5. The Cold-Chain facilities at these centres were adequate and functioning. However at the clinics, the storage condition deteriorated and the virus titres of vaccine tested ranged between log10-1,4 and log10-1,7. The Cold-Chain facilities were either non-functional or partially functional when they are present. Again there were no generator backups for power supply. The study showed that problem created by non-functional or partially functional Cold-Chain facilities resulted in the potency deterioration of rabies vaccine. It is therefore recommended that Cold-Chain facilities should be overhauled and backup generators be provided. Also recommended is the use of oral rabies vaccine that can stand the room temperature to vaccinate dogs.Keywords: rabies vaccine; potency; cold chain; veterinary clinics Nigerian Journal of Health and Biomedical Sciences Vol. 4(2) 2005: 112-11