RT Journal Article
T1 Double Deletion of EP402R and EP153R in the Attenuated Lv17/WB/Rie1 African Swine Fever Virus (ASFV) Enhances Safety, Provides DIVA Compatibility, and Confers Complete Protection Against a Genotype II Virulent Strain
A1 Gallardo, Carmina
A1 Mészáros, Itsván
A1 Soler, Alejandro
A1 Fernández Pinero, Jovita
A1 Van den Born, Erwin
A1 Simón, Alicia
A1 Casado, Nadia
A1 Nieto, Raquel
A1 Pérez, Covadonga
A1 Aldea, Irene
A1 López-Chavarrias, Vicente
A1 Göltl, Eszter
A1 Olasz, Ferenc
A1 Magyar, Tibor
A1 Zádori, Zoltán
A1 Sánchez-Vizcaíno Rodríguez, José Manuel
A1 Arias, Marisa
AB Background/Objectives: African swine fever virus (ASFV) is a devastating disease affecting domestic and wild suids and causing significant economic losses in the global pig industry. Attenuated modified live virus (MLV) vaccines are the most promising approaches for vaccine development. This study aimed to evaluate the safety and efficacy of four recombinant ASFV genotype II strains, derived from the non-hemadsorbing (non-HAD) attenuated isolate Lv17/WB/Rie1, through the single or simultaneous deletion of virulence-associated genes. Methods: Recombinant viruses were engineered by deleting the UK, EP402R, and EP153R genes, either individually or in combination. Four recombinant strains were evaluated for safety and efficacy in domestic pigs vaccinated intramuscularly with 102 TCID₅₀. Clinical signs, viremia, virus shedding, and antibody responses were monitored. Protection efficacy was assessed by challenging vaccinated pigs with the virulent genotype II Armenia07 strain. Additionally, a reversion-to-virulence study involving an overdose of the vaccine candidate was conducted to evaluate its stability through serial immunizations. Results: Deletion of the UK gene alone increased virulence, whereas the double deletion of EP402R and EP153R (Lv17/WB/Rie1-ΔCD) significantly enhanced safety while maintaining full protective efficacy. Vaccinated pigs exhibited reduced viremia, no virus shedding, and robust virus-specific antibody responses, achieving complete protection against Armenia07. The reversion-to-virulence study revealed potential but limited pathogenicity after multiple passages, indicating areas for improvement in vaccine stability. Conclusions: The Lv17/WB/Rie1-ΔCD strain demonstrates excellent safety and efficacy, along with potential DIVA (differentiating infected from vaccinated animals) compatibility, positioning it as a strong candidate for an ASFV MLV vaccine. Further research is needed to refine the vaccine and address the potential risks of reversion to virulence.
PB MDPI
SN 2076-393X
YR 2024
FD 2024-12-13
LK https://hdl.handle.net/20.500.14352/114034
UL https://hdl.handle.net/20.500.14352/114034
LA eng
NO Gallardo, C.; Mészáros, I.; Soler, A.; Fernandez-Pinero, J.; van den Born, E.; Simón, A.; Casado, N.; Nieto, R.; Perez, C.; Aldea, I.; et al. Double Deletion of EP402R and EP153R in the Attenuated Lv17/WB/Rie1 African Swine Fever Virus (ASFV) Enhances Safety, Provides DIVA Compatibility, and Confers Complete Protection Against a Genotype II Virulent Strain. Vaccines 2024, 12, 1406. https://doi.org/ 10.3390/vaccines12121406
NO Author Contributions: Conceptualization, C.G., I.M., E.v.d.B., Z.Z., J.M.S.-V. and M.A.; Data curation, C.G.; Formal analysis, C.G., J.F.-P., E.v.d.B., R.N., Z.Z. and M.A.; Funding acquisition, J.M.S.-V. and M.A.; Investigation, C.G., A.S. (Alejandro Soler), I.A., V.L.-C. and Z.Z.; Methodology, A.S. (Alejandro Soler), A.S. (Alicia Simón), N.C., C.P., E.G., F.O., T.M. and Z.Z.; Project administration, J.M.S.-V. and M.A.; Supervi-sion, C.G. and M.A.; Validation, C.G.; Visualization, C.G.; Writing—original draft, C.G.; Writing—review & editing, C.G., J.F.-P., E.v.d.B. and Z.Z. All authors have read and agreed to the published version of the manuscript.
NO European Commission
DS Docta Complutense
RD 27 jul 2026