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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Repeated vaccination against Haemonchus contortus provides continuous protection to young grazing sheep

Full text
Author(s):
Bassetto, Cesar C. [1] ; Almeida, Fabiana A. [1] ; Newlands, George F. J. [2] ; Smith, W. David [2] ; Amarante, Alessandro F. T. [1]
Total Authors: 5
Affiliation:
[1] UNESP Univ Estadual Paulista, Inst Biociencias, Botucatu, SP - Brazil
[2] Moredun Res Inst, Pentlands Sci Pk, Edinburgh, Midlothian - Scotland
Total Affiliations: 2
Document type: Journal article
Source: Veterinary Parasitology; v. 287, NOV 2020.
Web of Science Citations: 0
Abstract

Haemonchus contortus is the most important gastrointestinal nematode in the tropics and subtropics causing huge economic losses to the small ruminant industry. Vaccination is potentially a sustainable approach to control this parasite and the performance of Barbervax (R) a vaccine containing integral membrane glycoproteins from H. contortus intestinal cells, was evaluated in naturally infected grazing sheep during their development from sucking lambs to adults. The sheep were randomly assigned to two groups: Vaccine and Control. The Vaccine group were vaccinated 23 times over the course of this two-year trial at intervals of 3-6 weeks. They responded with anti-vaccine specific antibodies, had 80 % lower Haemonchus egg counts and were less anaemic compared with the controls. Packed cell volumes (PCV) were always greater than 25 % in the vaccinated sheep but averaged between 23 % and 24 % in the controls. Total plasma protein values were higher in the vaccinated group from the third vaccination until the end of the trial. Throughout the trial, 88 % of the control sheep were drenched (average of 3.1 drenches per treated animal) but only 57 % of vaccinates, needed a salvage anthel-mintic treatment (average of 1.9 drenches per treated animal), however, between group no differences in body weight were observed. In summary, these results indicate that a continuous course of Barbervax (R) can provide lambs with substantial year-round protection against H. contortus until they reached adulthood. (AU)

FAPESP's process: 15/00221-2 - Vaccination of sheep against Haemonchus contortus
Grantee:César Cristiano Bassetto
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 15/25718-7 - Prophylaxis of sheep worms using integrated crop-livestock system (ICL)
Grantee:Fabiana Alves de Almeida
Support Opportunities: Scholarships in Brazil - Post-Doctoral