Passive transfer and rate of decay of maternal antibody against African horse sickness virus in South African Thoroughbred foals

J. E. Crafford, C. W. Lourens, Ian Gardner, Nigel J Maclachlan, A. J. Guthrie

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Reasons for performing study: African horse sickness is an insect-transmitted, noncontagious disease of equids caused by African horse sickness virus (AHSV). Mortality can exceed 90% in fully susceptible horse populations. A live-attenuated (modified live) cell-culture-adapted (MLV) polyvalent AHSV vaccine is widely used to control African horse sickness in endemic areas in southern Africa. Field studies detailing antibody responses of vaccinated horses are lacking. Objectives: To determine antibody titres to the 9 known serotypes of AHSV in a cohort of broodmares that were regularly vaccinated with the MLV AHSV vaccine and to measure the passive transfer and rate of decay of maternal antibody to the individual virus serotypes in foals. Methods: Serum was collected from 15 mares before foaling and from their foals after foaling and monthly thereafter for 6 months. Antibody titres to each of the 9 AHSV serotypes were determined by serum virus neutralisation assay. Results: There was marked variation in the antibody response of the mares to individual AHSV serotypes even after repeated vaccination, with consistently higher titre responses to some virus serotypes. Likewise, the duration of maternally derived antibodies in foals differed among serotypes. Conclusions: Data from this study confirm variation of the neutralising antibody response of individual mares to repeated vaccination with polyvalent AHSV vaccine. Virus strains of individual AHSV serotypes included in the vaccine may vary in their inherent immunogenicity. Passively acquired maternal antibodies to AHSV vary markedly among foals born to vaccinated mares, with further variation in the duration of passive immunity to individual AHSV serotypes. Potential relevance: These data are relevant to the effective utilisation of live-attenuated AHSV vaccines in endemic regions, and potentially to the use of vaccines in response to future incursions of AHSV into previously free regions. Further studies involving a larger population will be required to determine the optimal time for vaccinating foals.

Original languageEnglish (US)
Pages (from-to)604-607
Number of pages4
JournalEquine Veterinary Journal
Volume45
Issue number5
DOIs
StatePublished - Sep 2013

Fingerprint

African Horse Sickness Virus
African horse sickness virus
maternal immunity
foals
deterioration
Mothers
Antibodies
serotypes
Vaccines
mares
vaccines
African Horse Sickness
antibodies
African horse sickness
Viruses
Antibody Formation
foaling
neutralization tests
viruses
Horses

Keywords

  • African horse sickness virus
  • Antibody half-life
  • Horse
  • Maternal antibody
  • Neutralising antibody
  • Passive transfer

ASJC Scopus subject areas

  • Equine

Cite this

Passive transfer and rate of decay of maternal antibody against African horse sickness virus in South African Thoroughbred foals. / Crafford, J. E.; Lourens, C. W.; Gardner, Ian; Maclachlan, Nigel J; Guthrie, A. J.

In: Equine Veterinary Journal, Vol. 45, No. 5, 09.2013, p. 604-607.

Research output: Contribution to journalArticle

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