Humoral response to an equine encephalitis vaccine in healthy alpacas.
OBJECTIVE
To determine humoral responses to an equine encephalitis vaccine in healthy alpacas.


METHODS
Clinical trial.


METHODS
39 healthy alpacas on 1 farm and 86 healthy alpacas on a second farm.


METHODS
All alpacas were given 3 doses IM of a bivalent, killed-virus equine encephalitis vaccine, with 4 weeks between doses. Eastern equine encephalitis (EEE) virus neutralizing antibody responses were determined with a plaque reduction neutralization assay every 14 days in alpacas on the first farm and 70 days after the first dose of vaccine on the second farm.


RESULTS
For alpacas on the first farm, geometric mean virus neutralizing antibody titer peaked 2 weeks after the third vaccine dose was given (ie, day 70). At this time, 29 of 38 (76%) animals were seropositive for antibodies against EEE virus, and percentage of animals <or= 2 years old that were seropositive (16/17) was significantly higher than percentage of animals > 6 years old that were seropositive (1/5). For alpacas on the second farm, 76 (88%) were seropositive on day 70, and percentage of animals <or= 2 years old that were seropositive (24/24) was significantly higher than percentage of animals > 6 years old that were seropositive (27/33). For both farms, geometric mean titer on day 70 was significantly higher in animals < 2 years old than in animals > 6 years old.


CONCLUSIONS
Results suggested that inoculation of alpacas with 3 doses of a bivalent, killed-virus equine encephalitis vaccine induced a humoral antibody response against EEE virus.
Bedenice
Daniela
D
Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA.
Bright
Amy
A
Pedersen
Douglas D
DD
Dibb
Jack
J
D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis* / Q000097:blood; D000917:Antibody Formation; D002161:Camelids, New World / Q000097:blood / Q000276:immunology* / Q000821:virology; D004306:Dose-Response Relationship, Immunologic; D004663:Encephalitis Virus, Eastern Equine / Q000276:immunology*; D020242:Encephalomyelitis, Eastern Equine / Q000097:blood / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D005260:Female; D007273:Injections, Intramuscular / Q000662:veterinary; D008297:Male; D014611:Vaccination / Q000662:veterinary; D015164:Vaccines, Inactivated; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*
D000914:Antibodies, Viral; D015164:Vaccines, Inactivated; D014765:Viral Vaccines