Protection against oronasal challenge with virulent feline leukaemia virus lasts for at least 12 months following a primary course of immunisation with Leukocell 2 vaccine.
The duration of immunity provided by a feline leukemia virus (FeLV) vaccine, Leukocell 2, was determined. Kittens were vaccinated when 9 and 12 weeks of age and were challenged 12 months later with FeLV-A/Glasgow-1. An oronasal challenge protocol without corticosteroid enhancement was developed in order to induce a persistent viraemia in a high proportion of adult cats. Fourteen of 18 (80%) of the vaccinated cats challenged in this way remained non-viraemic while 9/15 (60%) of age-matched controls became persistently infected, a preventable fraction of 63%. This difference was statistically significant (P=0.038). For comparison, 10 of 12 (83%) 15-17-week-old kittens challenged in the same way became persistently infected, confirming the relative resistance of adult animals to FeLV. Tests for virus neutralising and anti-feline oncornavirus-associated cell membrane antigen (FOCMA) antibodies suggested that the former were more important than the latter in protection. Thus, Leukocell 2 protected a significant proportion of cats from FeLV challenge 1 year after primary vaccination as kittens.
Harbour
D A
DA
Department of Clinical Veterinary Science, Division of Molecular and Cellular Biology, University of Bristol, Langford House, Langford, Bristol BS40 5DU, UK. dave.harbour@bristol.ac.uk
Gunn-Moore
D A
DA
Gruffydd-Jones
T J
TJ
Caney
S M A
SM
Bradshaw
J
J
Jarrett
O
O
Wiseman
A
A
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000097:blood; D002371:Cat Diseases / Q000276:immunology / Q000517:prevention & control*; D002415:Cats; D005260:Female; D015683:Gene Products, gag / Q000097:blood / Q000276:immunology; D005256:Leukemia Virus, Feline / Q000276:immunology* / Q000472:pathogenicity; D008297:Male; D009055:Mouth; D009500:Neutralization Tests; D009666:Nose; D012192:Retroviridae Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D012191:Retroviridae Proteins / Q000097:blood / Q000276:immunology; D015682:Retroviridae Proteins, Oncogenic / Q000008:administration & dosage*; D013997:Time Factors; D014412:Tumor Virus Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D014765:Viral Vaccines / Q000008:administration & dosage*; D014766:Viremia / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary; D014774:Virulence
D000914:Antibodies, Viral; D000956:Antigens, Viral; D015683:Gene Products, gag; D012191:Retroviridae Proteins; D015682:Retroviridae Proteins, Oncogenic; D014765:Viral Vaccines; C117471:feline leukemia virus protein p27; C045569:feline leukemia virus vaccine