Full Length Research Paper

Formulation of novel trehalose flakes for storage and delivery of newcastle disease (strain I-2) vaccine to chickens

P. N. Wambura

Department of Veterinary Microbiology and Parasitology, Sokoine University of Agriculture, P. O. Box 3019, Morogoro, Tanzania.

E-mail: phil_wambura@yahoo.com or pwambura@suanet.ac.tz.

Tel: 255 23 2603511-4, 4557, 255 744 638 460. Fax: 255 23 2604647.

Accepted 21 November, 2008

   Abstract

Newcastle disease (ND) strain I-2 vaccine flakes were formulated by using an amorphous trehalose sugar as a stabilizer and evaluated for long term storage and delivery to chickens. The results showed that the I-2 virus stored in trehalose flakes maintained its infectivity titre at 10^8.6 EID ₅₀/0.1 mL for 4 weeks at ambient room temperature. The vaccine flakes were stable after storage for 16 weeks while maintaining the infectivity titre of 10^7.5 EID ₅₀/0.1 mL. The results further indicated that the infectivity titres for ND virus recovered from flakes and liquid vaccine were similar. The findings from the present study showed the vaccine flakes are easily transported and readily released into a fluid phase when mixed with water; they can be administered orally without mixing with feeds and hence suitable for individual or mass vaccination of semi-feral scavenging village chickens. Chickens vaccinated orally with the flakes developed antiviral antibodies and resisted challenge with virulent strain of ND virus. The formulation of trehalose vaccine flakes could be a useful way to store and deliver ND vaccines to village chicken flocks in rural areas, particularly in developing countries if it is optimised.

Key words: Newcastle disease, strain I-2, trehalose flakes, antibody response.