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Updated: Apr 6, 2026
Immunization of Alpacas Lama pacos with Protein Antigens and Production of Antigen-specific Single Domain Antibodies
Published on: January 26, 2019
Lambs immunized with an inactivated variant of Anaplasma phagocytophilum
Snorre Stuen1, Wenche Okstad2, Karin Artursson3
1Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, Kyrkjevegen 332/334, 4325, Sandnes, Norway. snorre.stuen@nmbu.no.
Background:
Anaplasma phagocytophilum (formerly Ehrlichia phagocytophila) is an obligate intracellular bacterium causing the disease tick-borne fever (TBF) in domestic ruminants. An effective vaccine against the infection has been demanded for livestock by sheep farmers and veterinary practitioners for years.
Findings:
In the present study, we immunized lambs with an inactivated suspension of 1 × 10(8) killed A. phagocytophilum organisms mixed with adjuvant (Montanide ISA 61VG; Seppic). Twelve 9-months-old lambs of the Norwegian White Sheep breed were used. A full two-dose series of immunization was given subcutaneously to six lambs with a 4 week interval between injections. One month after the last immunization, all lambs were challenged with the homologous viable variant of A. phagocytophilum. After challenge, all lambs showed clinical responses for several days, although the immunized lambs reacted with an anamnestic response, i.e. significant reduction in infection rate and a significantly higher antibody titer.
Conclusion:
Immunization with inactivated A. phagocytophilum did not protect lambs TBF.
