Abstract

1Domingue G*, 1Peters, A 2Muhairwa AP, 2Chiwanga GH, 2Msoffe PL, 3 Jaglarz A, 4Wachira J, 4Musau AM, 4Kyangu NK and 1 Thevasagayam S

Two Good Clinical Practice studies are described. Firstly, the safety and efficacy of live, attenuated LaSota and l-2 Newcastle Disease (ND) vaccines and inactivated, adjuvanted ITA-NEW ND vaccine were evaluated in eightday old local ecotype chicks. For all vaccines safety and efficacy were satisfactory and serological titres exceeded the putative protective level of >2 3 before 14 days post-vaccination. The vaccinated groups displayed no significant differences. The data suggest that these vaccines are effective in very young village poultry. Secondly, in 35 day-old ISA-Brown pullets, MSD a 10x field dose formulation of Clone 30 vaccine, was compared to I-2 after a heat-stress test approximating to local conditions of delivery and use (24h, 32.3oC, in the dark). By 14 days post-vaccination, the heated MSD vaccine and heated I-2 titres exceeded 23 but the response of the heated MSD group was significantly higher than the heated I-2 group. Non-heated MSD induced a very rapid and higher response than those induced by the heated vaccines, as by 7 days post-vaccination, a 2 3 titre was reached and exceeded (GMT 4.0). The 10x normal field dose approach to conferring thermotolerance to live vaccines appears to be a simple, cheap and pragmatic method for use in hot climates.