Comparative Efficacy Studies With 3 Attenuated Live Newcastle Disease Vaccines in SPF and Commercial Chickens
Guittet M.¹, H. Le Coq¹, Y. Gardin² and S. Comte³. ¹VIPAC unit, AFSSA – 22400 Ploufragan - France ²SOLEIL sarl, 56 rue de la petite Cabane, 33230 Coutras – France ³Ceva Santé Animale – 33501 Libourne – France.A comparison was conducted in SPF and commercial chickens to evaluate the efficacy of several Newcastle Disease vaccines against a virulent challenge at 21 day-old. Three commercially available vaccines against Newcastle disease were compared : one pneumotropic strain, Vaccine A (Nobilis®Clone 30) and two reputed enterotropic strains, Vaccine B (Avinew®) and Vaccine C (Cevac®Vitapest L). One dose of vaccine was administered by eye drop or coarse spray to day-old chicks. Two different virulent strains were used to challenge the birds : Herts33 strain and Ploufragan strain, intramuscularly injected at 10 ELD per bird. The protection provided by these vaccines was evaluated over 2-week period following the challenge. Serological monitoring was also applied to all the groups. The virulent challenge results generally illustrate the high efficacy of the vaccines presented as well as their ability to protect poultry against a very severe Newcastle disease challenge, whatever the challenge strain used (Table 1).
Table 1. Mortality and morbidity noted after virulent challenge at 21 days. Percentage level of protection. | |||||
Experiments | Vaccine | Route | Dead/Total | Sick/Total | Protection (%) |
---|---|---|---|---|---|
SPF chicks, Herts 33 challenge Strain | Controls Vaccine A Vaccine B Vaccine C Vaccine C |
- E.D. E.D. E.D. Spray |
50/50 0/53 0/54 0/55 0/55 |
0 0/53 0/54 0/55 0/55 |
0 100 100 100 100 |
SPF chicks, Ploufragan challenge Strain | Controls Vaccine A Vaccine B Vaccine C Vaccine C |
- E.D. E.D. E.D. Spray |
50/50 0/53 3/54 1/55 0/55 |
0 1/53 2/54 2/55 0/55 |
0 98.1 90.7 94.5 100 |
Commercial chicks Herts 33 challenge Strain | Controls Vaccine A Vaccine B Vaccine C |
- E.D. E.D. E.D. |
47/55 7/56 1/55 2/55 |
8/55 3/56 1/55 1/55 |
0 82.2 96.4 94.6 |
A clear antibody response was noted in every vaccinated group. Whatever the vaccine and the challenge strains, SPF and commercial birds were protected according to the European Pharmacopoeia requirements.
Published in the XXIth World Veterinary Poultry Association CONGRESS – 28th Jan –1st Feb 2002