Colostral antibody induced interference ofinactivated bluetongue serotype-8 vaccinesin calves
2011
VITOUR, DAMIEN | Guillotin, Jean | Sailleau, Corinne | Viarouge, Cyril | DESPRAT, Alexandra | Wolff, Fréderic | Belbis, Guillaume | Durand, Benoit | Bakkali, Labib | Bréard, Emmanuel | Zientara, Stephan | Zanella, Gina
Since its introduction into northern Europe in 2006, bluetongue has become a major threat to animal health. Whilethe efficacy of commercial vaccines has been clearly demonstrated in livestock, little is known regarding the effectof maternal immunity on vaccinal efficacy. Here, we have investigated the duration and amplitude of colostralantibody-induced immunity in calves born to dams vaccinated against bluetongue virus serotype 8 (BTV-8) and theextent of colostral antibody-induced interference of vaccination in these calves. Twenty-two calf-cow pairs wereincluded in this survey. The median age at which calves became seronegative for BTV was 84 and 112 days asassayed by seroneutralisation test (SNT) and VP7 BTV competitive ELISA (cELISA), respectively. At the mean age of118 days, 13/22 calves were immunized with inactivated BTV-8 vaccine. In most calves vaccination elicited a weakimmune response, with seroconversion in only 3/13 calves. The amplitude of the humoral response to vaccinationwas inversely proportional to the maternal antibody level prior to vaccination. Thus, the lack of response wasattributed to the persistence of virus-specific colostral antibodies that interfered with the induction of the immuneresponse. These data suggest that the recommended age for vaccination of calves born to vaccinated dams needsto be adjusted in order to optimize vaccinal efficacy.
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