Prime-boost vaccination using DNA and whole inactivated virus vaccines provides limited protection against virulent feline immunodeficiency virus.
Protection against feline immunodeficiency virus (FIV) has been achieved using a variety of vaccines notably whole inactivated virus (WIV) and DNA. However protection against more virulent isolates, typical of those encountered in natural infections, has been difficult to achieve. In an attempt to improve protection against virulent FIV(GL8), we combined both DNA and WIV vaccines in a "prime-boost" approach. Thirty cats were divided into four groups receiving vaccinations and one unvaccinated control group. Following viral challenge, two vaccinated animals, one receiving DNA alone and one the prime-boost vaccine remained free of viraemia, whilst all controls became viraemic. Animals vaccinated with WIV showed apparent early enhancement of infection at 2 weeks post challenge (pc) with higher plasma viral RNA loads than control animals or cats immunised with DNA alone. Despite this, animals vaccinated with WIV or DNA alone showed significantly lower proviral loads in peripheral blood mononuclear cells and mesenteric lymph node cells, whilst those receiving the DNA-WIV prime-boost vaccine showed significantly lower proviral loads in PBMC, than control animals, at 35 weeks pc. Therefore both DNA and WIV vaccines conferred limited protection against viral challenge but the combination of WIV and DNA in a prime-boost approach appeared to offer no significant advantage over either vaccine alone.
Dunham
Stephen P
SP
Retrovirus Research Laboratory, Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Bearsden Road, Glasgow G61 1QH, United Kingdom. s.dunham@vet.gla.ac.uk
Bruce
Jennifer
J
Klein
Dieter
D
Flynn
J Norman
JN
Golder
Matthew C
MC
MacDonald
Susan
S
Jarrett
Oswald
O
Neil
James C
JC
D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis / Q000096:biosynthesis; D002415:Cats; D004797:Enzyme-Linked Immunosorbent Assay; D016181:Feline Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000517:prevention & control*; D007111:Immunity, Cellular / Q000276:immunology; D007115:Immunization Schedule; D007117:Immunization, Secondary; D016089:Immunodeficiency Virus, Feline / Q000276:immunology*; D019426:Integrases / Q000235:genetics / Q000276:immunology; D007371:Interferon-gamma / Q000378:metabolism; D008198:Lymph Nodes / Q000821:virology; D016131:Lymphocyte Subsets / Q000276:immunology / Q000821:virology; D012367:RNA, Viral / Q000097:blood; D013154:Spleen / Q000821:virology; D019444:Vaccines, DNA / Q000276:immunology; D015164:Vaccines, Inactivated / Q000276:immunology; D019562:Viral Load; D014765:Viral Vaccines / Q000627:therapeutic use*; D014766:Viremia / Q000276:immunology / Q000821:virology
D000914:Antibodies, Viral; D012367:RNA, Viral; D019444:Vaccines, DNA; D015164:Vaccines, Inactivated; D014765:Viral Vaccines; D007371:Interferon-gamma; D019426:Integrases