Humoral response to an equine encephalitis vaccine in healthy alpacas.

Abstract

OBJECTIVE:

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

DESIGN:

Clinical trial.

ANIMALS:

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

PROCEDURES:

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 AND CLINICAL RELEVANCE:

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.

• Authors: Daniela Bedenice, Amy Bright, Douglas D Pedersen, Jack Dibb
• Journal: Journal of the American Veterinary Medical Association (J Am Vet Med Assoc) Vol. 234 Issue 4 Pg. 530-4 (Feb 15 2009) ISSN: 0003-1488 [Print] United States
• PMID: 19222365 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Viral
• Vaccines, Inactivated
• Viral Vaccines

Topics

• Animals
• Antibodies, Viral (biosynthesis, blood)
• Antibody Formation
• Camelids, New World (blood, immunology, virology)
• Dose-Response Relationship, Immunologic
• Encephalitis Virus, Eastern Equine (immunology)
• Encephalomyelitis, Eastern Equine (blood, immunology, prevention & control, veterinary)
• Female
• Injections, Intramuscular (veterinary)
• Male
• Vaccination (veterinary)
• Vaccines, Inactivated
• Viral Vaccines (administration & dosage, immunology)