Immunological response to Brucella abortus strain 19 vaccination of cattle in a communal area in South Africa

Authors

  • Gregory J.G Simpson University of Pretoria
  • Tanguy Marcotty VERDI-R&D
  • Elodie Rouille National Veterinary College of Toulouse
  • Abel Chilundo Universidade Eduardo Mondlane
  • Jean-Jacques Letteson University of Namur
  • Jacques Godfroid University of Tromsø

Abstract

Brucellosis is of worldwide economic and public health importance. Heifer vaccination with live attenuated Brucella abortus strain 19 (S19) is the cornerstone of control in low- and middle-income countries. Antibody persistence induced by S19 is directly correlated with the number of colony-forming units (CFU) per dose. There are two vaccination methods: a ‘high’ dose (5–8 × 1010 CFU) subcutaneously injected or one or two ‘low’ doses (5 × 109 CFU) through the conjunctival route. This study aimed to evaluate serological reactions to the ‘high’ dose and possible implications of the serological findings on disease control. This study included 58 female cases, vaccinated at Day 0, and 29 male controls. Serum was drawn repeatedly and tested for Brucella antibodies using the Rose Bengal Test (RBT) and an indirect enzyme-linked immunosorbent assay (iELISA). The cases showed a rapid antibody response with peak RBT positivity (98%) at 2 weeks and iELISA (95%) at 8 weeks, then decreased in an inverse logistic curve to 14% RBT and 32% iELISA positive at 59 weeks and at 4.5 years 57% (4/7 cases) demonstrated a persistent immune response (RBT, iELISA or Brucellin skin test) to Brucella spp. Our study is the first of its kind documenting the persistence of antibodies in an African communal farming setting for over a year to years after ‘high’ dose S19 vaccination, which can be difficult to differentiate from a response to infection with wild-type B. abortus. A recommendation could be using a ‘low’ dose or
different route of vaccination.

Author Biographies

  • Gregory J.G Simpson, University of Pretoria

    Department of Production Animal Studies, University of Pretoria, South Africa

  • Tanguy Marcotty, VERDI-R&D

    VERDI-R&D, Louveigné, Belgium

  • Elodie Rouille, National Veterinary College of Toulouse

    National Veterinary College of Toulouse, Toulouse, France

  • Abel Chilundo, Universidade Eduardo Mondlane

    Department of Clinics, Universidade Eduardo Mondlane, Mozambique

  • Jean-Jacques Letteson, University of Namur

    Research Unit in Microorganisms Biology, Faculty of Science, University of Namur, Belgium

  • Jacques Godfroid, University of Tromsø

    Department of Artic and Marine Biology, University of Tromsø, Norway

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Published

2021-12-09

Issue

Section

Original Research