The Comparative Immunogenicity Of Three Lentogenic Brands Of Newcastle Disease Vaccines In Nigeria

Abstract

The comparative immunogenicity of a new lentogenic viscerotropic Newcastle disease vaccine, NDvac-1 (VG/GA strain) and two other existing proprietary pneumotropic lentogenic Newcastle disease vaccines in Nigeria, NDvac-2 (R2B) and NDvac-3 (LaSota) were studied. Immunogenicity was assessed on the basis of antibody production and protectively ratio indices following experimental challenge. Results showed that the relatively high pre-vaccination maternal haemagglutination-inhibition antibody titres were counter-productive to effective vaccination at day old. The mean geometric titres were 2.4, 3.5, 2.1 and 4.4 for NDvac-1, double dose NDvac-1, NDvac-2 and NDvac-3 vaccinated groups respectively at day 20 post vaccination. The protection indices were 2.5, 2.5, 1.5, 3.0 and 1.0 for NDvac-1; double dose NDvac-1, NDvac-2, NDvac-3 and the unvaccinated control group respectively following experimental challenge. These results therefore presented superior immunogenicity shared by NDvac-3 and NDvac-1 while NDvac-2 was found to be the least immunogenic of the three vaccines.

Keywords: Comparative immunogenicity, Newcastle disease vaccines

Nigerian Veterinary Journal Vol. 28 (2) 2007 pp. 1-5