03144naa a2200409 a 450000100080000000500110000800800410001902200140006002400340007410000180010824501490012626000090027550006530028452012470093765300110218465300130219565300180220865300210222665300490224765300280229665300280232465300170235265300110236965300260238070000200240670000160242670000280244270000170247070000150248770000230250270000190252570000190254470000180256370000230258170000170260477301130262110635822022-09-27       2022    bl uuuu     u00u1 u    #d  a2076-393X7 a10.3390/vaccines100811752DOI1 aHECKER, Y. P.  aReactivation and foetal infection in pregnant heifers infected with Neospora caninum live tachyzoites at prepubertal age.h[electronic resource]  c2022  aArticle history: Received 5 July 2022; Revised 14 July 2022; Accepted 22 July 2022; Published 25 July 2022.  Corresponding author:  Hecker, Y.P.; Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible (IPADS), Instituto Nacional de Tecnología Agropecuaria (INTA)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Balcarce, Argentina; email:hecker.yanina@inta.gob.ar --  Article: Gold Open Access, Green Open Access. -- Academic Editor: S. Louise Cosby. -- This article belongs to the Special Issue Vaccines in Farm Animals: https://www.mdpi.com/journal/vaccines/special_issues/Farm_Vaccines   --  aABSTRACT.- Neospora caninum is recognised for causing cattle abortion, provoking severe economic losses in the livestock industry worldwide. The aim of the present study was to evaluate the reactivation and foetal infection in pregnant heifers inoculated with live N. caninum tachyzoites before puberty. A total of 15 30-month-old pregnant heifers were allocated into four groups: animals inoculated with live tachyzoites of NC-Argentina LP1 isolate before puberty and challenged with live tachyzoites of NC-1 strain at 210 days of gestation (DG) (Group A); animals mock inoculated before puberty and challenged with NC-1 strain at 210 DG (Group B), animals inoculated before puberty but not subsequently challenged (Group C); and noninfected and nonchallenged animals (Group D). The results of this study showed that 100% of animals infected before puberty (Groups A and C) suffered reactivation of the infection at the seventh month of gestation. In addition, in three and two calves from Groups A and C, respectively, congenital infection was confirmed. Interestingly, we provide evidence that the use of live N. caninum tachyzoites in young animals as a strategy to induce protection is neither safe nor effective. © 2022 by the authors.  aBovine  aEfficacy  aLive parasite  aNeospora caninum  aPLATAFORMA DE INVESTIGACIÓN EN SALUD ANIMAL  aPLATAFORMA SALUD ANIMAL  aPrepubertal inoculation  aReactivation  aSafety  aVertical transmission1 aBURUCÚA, M. M.1 aFIORANI, F.1 aMALDONADO RIVERA, J. E.1 aCIRONE, K.M.1 aDORSCH, M.1 aCHEUQUEPÁN, F. A.1 aCAMPERO, L. M.1 aCANTÓN, G. J.1 aMARÍN, M. S.1 aORTEGA-MORA, L. M.1 aMOORE, D. P.  tVaccines, 2022, Volume 10, Issue 8, article 1175. OPEN ACCESS. doi: https://doi.org/10.3390/vaccines10081175