“…It has been observed that many BRSV infection models failed to reproduce the severe clinical signs of the disease, complicating the evaluation of vaccine efficacy ( Belknap et al, 1995 , Blodörn et al, 2015 , Taylor, 2013 ). In these studies, efficacy was demonstrated in newborn calves both in the absence of BRSV-specific MDAs ( Ellis et al, 2007 , Vangeel et al, 2007 ) and in their presence ( Ellis et al, 2013 , Hill et al, 2012 ). However, the absence of maternal antibody interference is not always observed ( Ellis et al, 2010 ).…”