title: Three-year duration of immunity for feline herpesvirus and calicivirus evaluated in a controlled vaccination-challenge laboratory trial.
abstract: Feline vaccination guidelines recommend less frequent boosters for the core vaccines (rhinotracheitis, calicivirosis and infectious panleucopenia). Most guidelines recommend boosters at 3-yearly intervals after a basic vaccination including primary vaccination and revaccination one year later. The objective of this study was to assess the duration of immunity induced by PUREVAX(®) RCPCh FeLV, a non-adjuvanted vaccine against feline rhinotracheitis, calicivirosis, infectious panleucopenia, chlamydiosis and leukemia. After primary vaccination followed by revaccination one year later with a vaccine formulated at minimum dose, the cats were kept in a confined environment and challenged 3 years later with a virulent heterologous strain of feline calicivirus (FCV) and subsequently a virulent strain of feline herpesvirus (FHV). Clinical signs and viral excretion were recorded for two weeks after each viral inoculation. Contemporary unvaccinated cats and new animals added at the time of challenge were used as controls. The vaccination regimen induced a stable and long-lasting humoral response. Vaccination resulted in a significant reduction in the severity of the disease after FHV challenge and in the frequency of cats showing a severe calicivirosis (defined as a combination of systemic clinical symptoms and oronasal ulcers). As opposed to the significant reduction of excretion observed a few weeks after primo-vaccination or even one year after vaccination for FCV, viral shedding was not reduced 3 years after revaccination. This study showed that primary vaccination and revaccination one year later with PUREVAX(®) RCPCh FeLV was able to induce 3-year duration of immunity against FCV and FHV. The results and conclusion of this study are consistent with current vaccination guidelines and will allow the veterinarian to adapt the vaccination regimen to the way of life of the cat.
authors.affiliation: Merial S.A.S., R&D, 254 avenue Marcel Mérieux, 69007 Lyon, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Jas
authors.affiliation: Merial S.A.S., R&D, 254 avenue Marcel Mérieux, 69007 Lyon, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Frances-Duvert
authors.affiliation: Merial S.A.S., R&D, 254 avenue Marcel Mérieux, 69007 Lyon, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Vernes
authors.affiliation: Merial S.A.S., R&D, 254 avenue Marcel Mérieux, 69007 Lyon, France.
authors.forename: Pierre-Michel
authors.initials: PM
authors.lastname: Guigal
authors.affiliation: Merial S.A.S., R&D, 254 avenue Marcel Mérieux, 69007 Lyon, France. Electronic address: herve.poulet@merial.com.
authors.forename: Hervé
authors.initials: H
authors.lastname: Poulet
mesh_terms: D000818:Animals; D017250:Caliciviridae Infections / Q000276:immunology / Q000662:veterinary*; D017927:Calicivirus, Feline / Q000276:immunology*; D002371:Cat Diseases / Q000276:immunology* / Q000821:virology*; D002415:Cats; D006564:Herpesviridae / Q000276:immunology*; D006566:Herpesviridae Infections / Q000276:immunology / Q000662:veterinary*; D007114:Immunization; D007117:Immunization, Secondary / Q000662:veterinary; D014611:Vaccination / Q000662:veterinary*; D014765:Viral Vaccines / Q000276:immunology*; D017201:Virus Shedding
chemical_list: D014765:Viral Vaccines
keywords: Calicivirus; Cat; Efficacy; Herpesvirus; Vaccine