title: Duration of serologic response to three viral antigens in cats.
abstract: OBJECTIVE
  To determine whether vaccinated cats either remained seropositive or responded serologically to revaccination against 3 key viral antigens after extended periods since their last vaccination.
  
  
  METHODS
  Serologic survey.
  
  
  METHODS
  272 healthy client-owned cats.
  
  
  METHODS
  Cats were > or = 2 years old and vaccinated for feline panleukopenia virus (FPV), feline calicivirus (FCV), and feline herpesvirus (FHV). On day 0, cats were revaccinated with a vaccine from the same line of vaccines as they had historically received. Antibody titers were measured in sera collected on day 0 (prevaccination titer) and 5 to 7 days later (postvaccination titer). Cats were considered to have responded serologically if they had a day-0 hemagglutination inhibition titer to FPV > or = 1:40, serum neutralization (SN) titer to FCV > or = 1:32, SN titer to FHV > or = 1:16, or > or = 4-fold increase in antibody titer after revaccination.
  
  
  RESULTS
  The percentage of cats that had titers at or above the threshold values or responded to revaccination with a > or = 4-fold increase in titer was 96.7% for FPV, 97.8% for FCV, and 88.2% for FHV.
  
  
  CONCLUSIONS
  In most cats, vaccination induced a response that lasted up to and beyond 48 months for all 3 antigens. Although not equivalent to challenge-of-immunity studies as a demonstration of efficacy, results suggest that revaccination with the vaccine used in our study provides adequate protection even when given less frequently than the traditional 1-year interval. The study provides valuable information for clinicians to determine appropriate revaccination intervals.
authors.affiliation: Veterinary Medicine Biologicals Research and Development, Pfizer Animal Health, Pfizer Inc, 7000 Portage Rd, Kalamazoo, MI 49001, USA.
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Mouzin
authors.forename: Marianne J
authors.initials: MJ
authors.lastname: Lorenzen
authors.forename: John D
authors.initials: JD
authors.lastname: Haworth
authors.forename: Vickie L
authors.initials: VL
authors.lastname: King
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000276:immunology*; D017927:Calicivirus, Feline / Q000276:immunology; D002371:Cat Diseases / Q000276:immunology / Q000517:prevention & control*; D002415:Cats; D028301:Feline Panleukopenia Virus / Q000276:immunology; D005260:Female; D006385:Hemagglutination Inhibition Tests / Q000662:veterinary; D006564:Herpesviridae / Q000276:immunology; D007117:Immunization, Secondary / Q000662:veterinary*; D008297:Male; D009500:Neutralization Tests / Q000662:veterinary; D016036:Seroepidemiologic Studies; D014765:Viral Vaccines; D014777:Virus Diseases / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D014765:Viral Vaccines