Abstract

EFFECTS OF TEMPERATURE ON STABILITY OF HAEMAGGLUTINATION TITERS OF STABILIZED NEWCASTLE DISEASE VACCINES

Ruth Enayi Guktur*, Patrick Olorunfemi, Chika Nwosu, Olayinka Asala and Nelson Ochekpe

¹National Veterinary Research Institute, Viral Vaccine Production Division, P.M.B. 01, Vom,Jos, Plateau State, Nigeria.

²Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, University ofJos, Plateau State, Nigeria.

³Department of Pharmaceutics & Pharmaceutical Technology, Faculty of PharmaceuticalSciences, University of Jos, Plateau State, Nigeria.

ABSTRACT

Newcastle disease (ND) is a viral disease caused by avian paramyxovirus type -1 (APMV-1), which is a single stranded RNA virus that affects many species of birds and causes severe economic losses in the poultry sector. Vaccine instability at ambient temperatures results in drop and eventual loss of infectivity leading to vaccination failure at the time of administration and is why vaccines are generally stored at refrigerated temperatures or as frozen formulations. This requires maintaining a cold chain from the time of manufacture to the point of administration and is expensive to achieve in many parts of the developing world. The haemagglutination (HA) test was used to study the influence of temperature on haemagglutination titers of a live viral veterinary vaccine stabilized with trehalose (a non reducing disaccharide) and peptone and stored at different temperatures. 5, 30 and 50% trehalose were prepared, autoclaved, tested for sterility, mixed with the wet harvest as stabilizer and conventionally freeze-dried with a GT-40 freeze dryer. The freeze-dried vaccines were grouped according to the strength of trehalose they contain alone, presence of peptone alone and the virus without any stabilizer and stored at 5ο C, 25 ο C, and 37ο C for a minimum of 6 months and the HA titers determined at intervals. It was observed that the stabilizers in the vaccines improved the stability of the haemagglutination titers as storage temperature increased.

Keywords: Newcastle disease, cold-chain, freeze-dried, haemagglutination, stability, trehalose.