Safety and efficacy studies of Newcastle Disease vaccines in very young African local ecotype chicks and in commercial pullets

Autor: Domingue, G, Peters, Andrew, Muhairwa, AP, Chiwanga, GH, Msoffe, PL, Jaglarz, A, Wachira, J, Musau, AM, Kyangu, NK, Thevasagayam, S
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Domingue, G, Peters, A, Muhairwa, AP, Chiwanga, GH, Msoffe, PL, Jaglarz, A, Wachira, J, Musau, AM, Kyangu, NK & Thevasagayam, S 2017, ' Safety and efficacy studies of Newcastle Disease vaccines in very young African local ecotype chicks and in commercial pullets ', African Journal of Poultry Farming, vol. 5, no. 3, pp. 177-184 .
Popis: 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 eight- day old local ecotype chicks. For all vaccines safety and efficacy were satisfactory and serological titres exceeded the putative protective level of >23 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 23 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.
Databáze: OpenAIRE