Glycoproteins gl and gE of feline herpesvirus-1 are virulence genes: safety and efficacy of a gl-gE deletion mutant in the natural host.
Feline rhinotracheitis virus (FRV) is an important upper respiratory tract pathogen of cats. FRV is a member of the subfamily Alphaherpesvirinae and is designated feline herpesvirus-1 (FHV-1). Besides upper respiratory clinical signs, FHV-1 may cause generalized infections in neonates or abortions in pregnant queens. Recently we described a recombinant FHV-1 strain with a deletion in the genes for glycoproteins gl and gE (FHB beta-galglgE delta) and reported that cats vaccinated subcutaneously with high doses of the recombinant FHV-1 strain responded with only mild clinical signs and developed strong immunity against subsequent virulent virus challenge. Here we compare the intranasal and subcutaneous routes of administration of this strain and assess its ability to induce protective immunity and prevent virus shedding after challenge. Cats vaccinated subcutaneously or intranasally with high doses of the recombinant FHV-1 strain responded with only mild clinical signs and developed strong immunity against subsequent virulent virus challenge. This was especially evident when the mutant vaccine was administered oronasally. In contrast, intranasal administration of two other FHV-1 isolates induced severe clinical signs in cats. We conclude from testing this FHV-1 mutant in the natural host that deletion of gE and a portion of gl genes strongly reduces viral virulence but that immunogenicity is maintained.
Kruger
J M
JM
Department of Small Animal Clinical Sciences, Michigan State University, East Lansing 48824, USA.
Sussman
M D
MD
Maes
R K
RK
D000280:Administration, Inhalation; D018138:Alphaherpesvirinae / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D002371:Cat Diseases / Q000276:immunology / Q000517:prevention & control / Q000821:virology*; D002415:Cats; D005260:Female; D017353:Gene Deletion; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology; D006566:Herpesviridae Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology; D007279:Injections, Subcutaneous; D008297:Male; D009500:Neutralization Tests; D014136:Tracheitis / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology; D014613:Vaccines, Attenuated / Q000235:genetics / Q000276:immunology; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*; D014765:Viral Vaccines / Q000235:genetics / Q000276:immunology*; D014774:Virulence / Q000235:genetics; D017201:Virus Shedding
D000914:Antibodies, Viral; D006023:Glycoproteins; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; D014759:Viral Envelope Proteins; D014765:Viral Vaccines