A single recall vaccination lapse in sows triggers PRRSV resurgence and boosts viral genetic diversity
Clilverd, Hepzibar (Universitat Autònoma de Barcelona. Departament de Sanitat i d'Anatomia Animals)
Martin-Valls, Gerard (Universitat Autònoma de Barcelona. Departament de Sanitat i d'Anatomia Animals)
Li, Yanli (Universitat Autònoma de Barcelona. Departament de Sanitat i d'Anatomia Animals)
Domingo Carreño, Ivan (Universitat Autònoma de Barcelona. Departament de Sanitat i d'Anatomia Animals)
Martín Castillo, Margarita (Universitat Autònoma de Barcelona. Departament de Sanitat i d'Anatomia Animals)
Cortey, Martí (Universitat Autònoma de Barcelona. Departament de Sanitat i d'Anatomia Animals)
Mateu de Antonio, Enrique María (Universitat Autònoma de Barcelona. Departament de Ciència Animal i dels Aliments)

Date:	2025
Abstract:	Porcine reproductive and respiratory syndrome virus (PRRSV) persists on certain farms despite vaccination and control efforts, with genetic diversity suspected as a contributing factor. This study examined the evolution and persistence dynamics of PRRSV-1 on a farrow-to-fattening farm with 1,700 sows vaccinated quarterly, focusing on a summer vaccination lapse. Over eight months, three farrowing batches were monitored from birth to nine weeks of age using virological (RT-qPCR, whole-genome, and ORF5 sequencing) and serological (ELISA and neutralizing antibody) analyses. An incident related to elevated temperatures during the summer involving unproper vaccine handling occurred during the last blanket vaccination, before sampling the third batch. Viral circulation was primarily confined to the nurseries, with a notable surge of incidence and mortality in this last batch, linked to lower maternal antibody levels likely due to vaccination failure. Phylogenetic analyses showed the persistence of the same viral strain throughout the study, with increased genetic diversity in Batch 3 driven by selection and recombination. Ultimately, reestablishing the vaccination program led to a PRRSV-positive-stable with vaccination status. Overall, a single vaccination lapse caused increased PRRSV-1 incidence and genetic diversity in weaners, linked to declining maternal antibody levels, underscoring the importance of strict vaccination adherence. The online version contains supplementary material available at 10. 1186/s40813-025-00433-w.
Grants:	Agencia Estatal de Investigación AGL2017-87073-R Ministerio de Economía y Competitividad FPU18/04259
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Porcine reproductive and respiratory syndrome virus (PRRSV) ; Vaccination ; Genetic diversity ; Evolution
Published in:	Porcine health management, Vol. 11 (may 2025) , ISSN 2055-5660

DOI: 10.1186/s40813-025-00433-w
PMID: 40340928

9 p, 2.0 MB

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