title: Further evaluation of higher potency vaccines for early protection of cattle against FMDV direct contact challenge.
abstract: The effect of administering higher payload FMD vaccines 10 days prior to severe direct contact challenge on protection from clinical disease and sub-clinical infection was investigated in cattle using two antigen payloads (single strength and 10-fold). Regardless of antigen payload, vaccination was shown to significantly reduce the number of clinically infected animals, and significantly reduce virus excretion shortly after challenge, when compared with the unvaccinated group (P<0.05). Although FMDV transmission occurred from single strength vaccinated infected cattle to similarly vaccinated cattle held in indirect contact, no disease was induced in these animals. These studies further confirm that emergency vaccination does significantly reduce clinical disease and sub-clinical virus replication and excretion, particularly early post exposure, thereby reducing the possibility of transmission between animals and herds. To be most effective, however, the results also substantiate that time of vaccination prior to challenge significantly influences the number of animals becoming infected, so the decision to vaccinate should be made swiftly, to allow maximum opportunity for protective immunity to develop.
authors.affiliation: Institute for Animal Health, Pirbright Laboratory, Ash Road Pirbright Surrey, GU24 0NF, United Kingdom. sarah.cox@bbsrc.ac.uk
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Cox
authors.forename: Satya
authors.initials: S
authors.lastname: Parida
authors.forename: Charlotte
authors.initials: C
authors.lastname: Voyce
authors.forename: Scott M
authors.initials: SM
authors.lastname: Reid
authors.forename: Pip A
authors.initials: PA
authors.lastname: Hamblin
authors.forename: Geoff
authors.initials: G
authors.lastname: Hutchings
authors.forename: David J
authors.initials: DJ
authors.lastname: Paton
authors.forename: Paul V
authors.initials: PV
authors.lastname: Barnett
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control*; D005536:Foot-and-Mouth Disease / Q000517:prevention & control*; D029544:Foot-and-Mouth Disease Virus / Q000276:immunology*; D008297:Male; D009960:Oropharynx / Q000821:virology; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014611:Vaccination; D014765:Viral Vaccines / Q000276:immunology*; D014766:Viremia / Q000517:prevention & control / Q000662:veterinary
chemical_list: D000914:Antibodies, Viral; D012367:RNA, Viral; D014765:Viral Vaccines