scholarly journals Thoughts on African Swine Fever Vaccines

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 943
Author(s):  
Daniel L. Rock
Keyword(s):  
African Swine Fever ◽  
Hemorrhagic Disease ◽  
Swine Industry ◽  
Export Markets ◽  
The Caucasus ◽  
Caucasus Region ◽  
Response And Recovery ◽  
Indefinite Future ◽  
Domestic Swine ◽  
The U.S

African swine fever (ASF) is an acute viral hemorrhagic disease of domestic swine with mortality rates approaching 100%. Devastating ASF outbreaks and continuing epidemics starting in the Caucasus region and now in the Russian Federation, Europe, China, and other parts of Southeast Asia (2007 to date) highlight its significance. ASF strain Georgia-07 and its derivatives are now endemic in extensive regions of Europe and Asia and are “out of Africa” forever, a situation that poses a grave if not an existential threat to the swine industry worldwide. While our current concern is Georgia-07, other emerging ASFV strains will threaten for the indefinite future. Economic analysis indicates that an ASF outbreak in the U.S. would result in approximately $15 billion USD in losses, assuming the disease is rapidly controlled and the U.S. is able to reenter export markets within two years. ASF’s potential to spread and become endemic in new regions, its rapid and efficient transmission among pigs, and the relative stability of the causative agent ASF virus (ASFV) in the environment all provide significant challenges for disease control. Effective and robust methods, including vaccines for ASF response and recovery, are needed immediately.

scholarly journals Subunit Vaccine Approaches for African Swine Fever Virus

Vaccines ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 56 ◽  
Author(s):  
Natasha N. Gaudreault ◽  
Juergen A. Richt
Keyword(s):  
Western Europe ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Swine Industry ◽  
Fatal Disease ◽  
The Caucasus ◽  
Caucasus Region ◽  
Highly Virulent ◽  
Genotype Ii

African swine fever virus (ASFV) is the cause of a highly fatal disease in swine, for which there is no available vaccine. The disease is highly contagious and poses a serious threat to the swine industry worldwide. Since its introduction to the Caucasus region in 2007, a highly virulent, genotype II strain of ASFV has continued to circulate and spread into Eastern Europe and Russia, and most recently into Western Europe, China, and various countries of Southeast Asia. This review summarizes various ASFV vaccine strategies that have been investigated, with focus on antigen-, DNA-, and virus vector-based vaccines. Known ASFV antigens and the determinants of protection against ASFV versus immunopathological enhancement of infection and disease are also discussed.

scholarly journals African Swine Fever Virus Georgia 2007 with a Deletion of Virulence-Associated Gene9GL(B119L), when Administered at Low Doses, Leads to Virus Attenuation in Swine and Induces an Effective Protection against Homologous Challenge

2015 ◽  
Vol 89 (16) ◽  
pp. 8556-8566 ◽  
Author(s):  
Vivian O'Donnell ◽  
Lauren G. Holinka ◽  
Peter W. Krug ◽  
Douglas P. Gladue ◽  
Jolene Carlson ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
Genetically Modified ◽  
African Swine Fever ◽  
Fever Virus ◽  
The Caucasus ◽  
Caucasus Region ◽  
Homologous Virus ◽  
Virulent Virus ◽  
Virulent Phenotype ◽  
Highly Virulent

ABSTRACTAfrican swine fever virus (ASFV) is the etiological agent of an often lethal disease of domestic pigs. Disease control strategies have been hampered by the unavailability of vaccines against ASFV. Since its introduction in the Republic of Georgia, a highly virulent virus, ASFV Georgia 2007 (ASFV-G), has caused an epizootic that spread rapidly into Eastern European countries. Currently no vaccines are available or under development to control ASFV-G. In the past, genetically modified ASFVs harboring deletions of virulence-associated genes have proven attenuated in swine, inducing protective immunity against challenge with homologous parental viruses. Deletion of the gene9GL(open reading frame [ORF] B119L) in highly virulent ASFV Malawi-Lil-20/1 produced an attenuated phenotype even when administered to pigs at 10650% hemadsorption doses (HAD50). Here we report the construction of a genetically modified ASFV-G strain (ASFV-G-Δ9GLv) harboring a deletion of the9GL(B119L) gene. Like Malawi-Lil-20/1-Δ9GL, ASFV-G-Δ9GL showed limited replication in primary swine macrophages. However, intramuscular inoculation of swine with 104HAD50of ASFV-G-Δ9GL produced a virulent phenotype that, unlike Malawi-Lil-20/1-Δ9GL, induced a lethal disease in swine like parental ASFV-G. Interestingly, lower doses (102to 103HAD50) of ASFV-G-Δ9GL did not induce a virulent phenotype in swine and when challenged protected pigs against disease. A dose of 102HAD50of ASFV-G-Δ9GLv conferred partial protection when pigs were challenged at either 21 or 28 days postinfection (dpi). An ASFV-G-Δ9GL HAD50of 103conferred partial and complete protection at 21 and 28 dpi, respectively. The information provided here adds to our recent report on the first attempts toward experimental vaccines against ASFV-G.IMPORTANCEThe main problem for controlling ASF is the lack of vaccines. Studies on ASFV virulence lead to the production of genetically modified attenuated viruses that induce protection in pigs but only against homologous virus challenges. Here we produced a recombinant ASFV lacking virulence-associated gene9GLin an attempt to produce a vaccine against virulent ASFV-G, a highly virulent virus isolate detected in the Caucasus region in 2007 and now spreading though the Caucasus region and Eastern Europe. Deletion of9GL, unlike with other ASFV isolates, did not attenuate completely ASFV-G. However, when delivered once at low dosages, recombinant ASFV-G-Δ9GL induces protection in swine against parental ASFV-G. The protection against ASFV-G is highly effective after 28 days postvaccination, whereas at 21 days postvaccination, animals survived the lethal challenge but showed signs of ASF. Here we report the design and development of an experimental vaccine that induces protection against virulent ASFV-G.

scholarly journals Serodiagnostic potential of synthetic peptides derived from African swine fever virus putative protein pCP312R

2019 ◽  
Author(s):  
Sylvester Ochwo ◽  
David Kalenzi Atuhaire ◽  
Mathias Afayoa ◽  
Majid Kisseka ◽  
Phillip Kimuda Magambo ◽  
...  
Keyword(s):  
Synthetic Peptides ◽  
Indirect Elisa ◽  
African Swine Fever Virus ◽  
Prediction Method ◽  
African Swine Fever ◽  
Diagnostic Sensitivity ◽  
Hemorrhagic Disease ◽  
Putative Protein ◽  
First Time ◽  
Domestic Swine

AbstractAfrican swine fever (ASF) is a hemorrhagic disease of domestic swine, with often high mortality rates registered. To date there is still no vaccine produced against ASF, and disease management in countries including Uganda, where the disease is endemic is dependent on accurate and timely diagnosis programs and quarantine. This study aimed at contributing more knowledge towards ASF diagnosis by investigating the serodiagnostic potential of synthetic peptides of an ASF putative protein pCP312R. Antigenic regions of the pCP312R putative protein were identified using Kolaskar and Tongaonkar antigenicity prediction method and twelve (12) peptides were predicted, out of which four (4) peptides were selected and synthesised. An additional peptide derived from the carboxyl end of the ASFV p54 protein was also synthesised and used as a control. Polyclonal rabbit antibodies raised against each of the five peptides was used in immunohistochemistry, and each demonstrated ability to localize viral antigen in pig tissue albeit with slightly varying intensities, at a dilution of 1:200, with antibodies against peptides cpr1, cpr2, cpr3 and cpr4 all accurately staining infected macrophages. However all the peptides evaluated in this study performed moderately when used in indirect ELISA tests giving the following results; CP1; diagnostic sensitivity of 55% (95% CI, 0.3421-0.7418) and specificity of 96% (95% CI, 0.8046-0.9929), CP2; diagnostic sensitivity of 100% (95% CI, 0.8389-1) and specificity of 52% (95% CI, 0.335-0.6997), CP3; diagnostic sensitivity of 95% (95% CI, 76.39-99.11) and specificity of 88% (95% CI, 70.04-95.83), CP4; diagnostic sensitivity of 90% (95% CI: 0.699-0.9721) and specificity of 76% (95% CI: 0.5657-0.885) and p54; diagnostic sensitivity of 100% (95% CI, 0.8389-1) and specificity of 56% (95% CI, 0.3707-0.7333). This study presents the first time synthetic peptides have been successfully predicted, designed and evaluated for Serodiagnosis of African swine fever in domestic pigs. This study in addition showed that there is potential for use of polyclonal anti-peptide antibodies in the diagnosis of ASF using immunohistochemistry.

scholarly journals ASFV-G-∆I177L as an Effective Oral Nasal Vaccine against the Eurasia Strain of Africa Swine Fever

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 765
Author(s):  
Manuel V. Borca ◽  
Elizabeth Ramirez-Medina ◽  
Ediane Silva ◽  
Elizabeth Vuono ◽  
Ayushi Rai ◽  
...  
Keyword(s):  
Western Europe ◽  
Vaccine Candidate ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Similar Efficacy ◽  
Economic Losses ◽  
Swine Industry ◽  
Nasal Vaccine ◽  
Domestic Swine ◽  
Highly Virulent

The African swine fever virus (ASFV) is currently causing a pandemic affecting wild and domestic swine from Western Europe to Asia. No commercial vaccines are available to prevent African swine fever (ASF), resulting in overwhelming economic losses to the swine industry. We recently developed a recombinant vaccine candidate, ASFVG-ΔI177L, by deleting the I177L gene from the genome of the highly virulent ASFV strain Georgia (ASFV-G). ASFV-G-ΔI177L has been proven safe and highly efficacious in challenge studies using parental ASFV-G. Here, we present data demonstrating that ASFV-G-ΔI177L can be administered by the oronasal (ON) route to achieve a similar efficacy to that of intramuscular (IM) administration. Animals receiving ON ASFV-G-ΔI177L were completely protected against virulent ASFV-G challenge. As previously described, similar results were obtained when ASFV-G-ΔI177L was given intramuscularly. Interestingly, viremias induced in animals inoculated oronasally were lower than those measured in IM-inoculated animals. ASFV-specific antibody responses, mediated by IgG1, IgG2 and IgM, do not differ in animals inoculated by the ON route from that had IM inoculations. Therefore, the ASFV-G-ΔI177L vaccine candidate can be administered oronasally, a critical attribute for potential vaccination of wild swine populations.

scholarly journals African Swine Fever Virus CD2v protein promotes β-Interferon expression and apoptosis in swine cells

2020 ◽  
Author(s):  
Sabal Chaulagain ◽  
Gustavo Delhon ◽  
Sushil Khatiwada ◽  
Daniel L. Rock
Keyword(s):  
Nuclear Translocation ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Lymphoid Tissues ◽  
Hemorrhagic Disease ◽  
Swine Industry ◽  
Lymphocyte Depletion ◽  
Viral Virulence ◽  
Induced Apoptosis

ABSTRACTAfrican swine fever (ASF) is a disease of swine characterized by massive lymphocyte depletion in lymphatic tissues due to apoptosis of B and T cells, most likely triggered by proteins or factors secreted by infected adjacent macrophages. Here we describe a role for the ASF virus (ASFV) protein CD2v in apoptosis induction in lymphocytes. CD2v is a viral homolog of host CD2 that has been implicated in viral virulence and immunomodulation in vitro; however, its actual function remains unknown. We show that CD2v is secreted into culture medium of CD2v-expressing swine cells; and expression of-or treatment with CD2v led to significant induction of IFN-β/ISGs transcription and antiviral state. CD2v expression led to enhanced NF-κB-p65 nuclear translocation in these cultures and incubation with a NF-κB inhibitor reduced CD2v-induced NF-κB-p65 nuclear translocation and IFN-β transcription. We show that CD2v binds CD58, the natural CD2 ligand, and that CD58 siRNA knock-down results in significant reduction in NF-κB-p65 nuclear translocation and IFN-β transcription. Treatment of swine PBMC with purified CD2v led to enhanced NF-κB-p65 nuclear translocation and induction of IFN-β transcription. Further, induction of caspase-3 and PARP1 cleavage was observed in these swine PBMC at later times, providing a mechanism for CD2v-induced apoptosis of lymphocytes. Finally, IFN-β induction and NF-κB activation was inhibited in swine PBMC treated with purified CD2v pre-incubated with antibodies against CD2v. Overall, our results indicate that ASFV CD2v is an immunomodulatory protein that, by promoting lymphocyte apoptosis, may contribute to bystander lymphocyte depletion observed during ASFV infection in pigs.IMPORTANCEASF, a severe hemorrhagic disease of domestic swine, represents a significant economic threat to swine industry worldwide. One critical pathological event observed in pigs infected with virulent isolates is an extensive destruction of lymphoid tissue and massive lymphocyte depletion. However, viral factor/s involved in this event are yet to be identified. Here we show that, by inducing NF-κB-dependent IFN signaling, ASFV CD2v is able to promote apoptosis in swine PBMC. We propose that CD2v released by ASFV-infected macrophages contributes to the massive depletion of lymphocytes observed in lymphoid tissues of infected pigs. Results here improve our understanding of ASFV pathogenesis and will encourage novel intervention approaches.

scholarly journals Computational Analysis of African Swine Fever Virus Protein Space for the Design of an Epitope-Based Vaccine Ensemble

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1078 ◽  
Author(s):  
Albert Ros-Lucas ◽  
Florencia Correa-Fiz ◽  
Laia Bosch-Camós ◽  
Fernando Rodriguez ◽  
Julio Alonso-Padilla
Keyword(s):  
T Cell ◽  
Vaccine Development ◽  
De Novo ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Economic Losses ◽  
Virus Protein ◽  
Hemorrhagic Disease ◽  
Starting Point

African swine fever virus is the etiological agent of African swine fever, a transmissible severe hemorrhagic disease that affects pigs, causing massive economic losses. There is neither a treatment nor a vaccine available, and the only method to control its spread is by extensive culling of pigs. So far, classical vaccine development approaches have not yielded sufficiently good results in terms of concomitant safety and efficacy. Nowadays, thanks to advances in genomic and proteomic techniques, a reverse vaccinology strategy can be explored to design alternative vaccine formulations. In this study, ASFV protein sequences were analyzed using an in-house pipeline based on publicly available immunoinformatic tools to identify epitopes of interest for a prospective vaccine ensemble. These included experimentally validated sequences from the Immune Epitope Database, as well as de novo predicted sequences. Experimentally validated and predicted epitopes were prioritized following a series of criteria that included evolutionary conservation, presence in the virulent and currently circulating variant Georgia 2007/1, and lack of identity to either the pig proteome or putative proteins from pig gut microbiota. Following this strategy, 29 B-cell, 14 CD4+ T-cell and 6 CD8+ T-cell epitopes were selected, which represent a starting point to investigating the protective capacity of ASFV epitope-based vaccines.

Genotype diversity of Bacillus anthracis strains isolated from the Caucasus region

2012 ◽  
Vol 27 (2) ◽  
pp. 74-78 ◽  
Author(s):  
E. I. Eremenko ◽  
A. G. Ryazanova ◽  
O. I. Tsygankova ◽  
E. A. Tsygankova ◽  
N. P. Buravtseva ◽  
...  
Keyword(s):  
Bacillus Anthracis ◽  
The Caucasus ◽  
Caucasus Region ◽  
Genotype Diversity
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