Special Issue "African Swine Fever Virus Prevention and Control"

A special issue of Vaccines (ISSN 2076-393X). This special issue belongs to the section "Veterinary Vaccines".

Deadline for manuscript submissions: 31 August 2020.

Special Issue Editor

Dr. Christopher Netherton
Website
Guest Editor
The Pirbright Institute, Surrey, United Kingdom
Interests: African swine fever, vaccines, host-pathogen interactions, virus assembly and replication, protective immunity, antigen discovery

Special Issue Information

Dear Colleagues,

Since its introduction into Georgia in 2007, African swine fever virus has spread across both Europe and Asia and has been responsible for the deaths of hundreds of millions of animals. Virulent strains of the virus cause a haemorhagic fever to occur in domestic pigs and wild boar that is invariably fatal. Current control measures based on rapid diagnosis, quarantine, and slaughter of affected animals have not been sufficient to prevent the disease from becoming established in different epidemiological situations across the globe. The main tools missing from the African swine fever control kit are vaccines suitable for preventing disease in both domestic and wild animals. Without such vaccines, it is difficult to envisage how the current epidemic can be brought under control and the disease eradicated. Novel approaches are required, as, to date, inactivated viruses and attenutation through tissue culture passage have not yielded safe and effective vaccines. The causative agent is a complex pathogen with a complex immunopathology that is not well-characterized. Mechanisms of protective immunity and protective antigens also remain to be fully described. Due to the severity of the current African swine fever virus epidemic, alternative strategies including prophylaxsis may also need to be considered. Deployment of such novel control strategies will require the development of effective implementaiton strategies based on robust epidemiological modeling.

Dr. Christopher Netherton
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Vaccines is an international peer-reviewed open access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • African swine fever vaccines
  • African swine fever prophalyxsis
  • vaccine delivery to swine
  • vaccine deployment strategies
  • African swine fever virus protective immunity
  • African swine fever antigen discovery and characterization

Published Papers (4 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle
How to Demonstrate Freedom from African Swine Fever in Wild Boar—Estonia as an Example
Vaccines 2020, 8(2), 336; https://doi.org/10.3390/vaccines8020336 - 25 Jun 2020
Cited by 1
Abstract
Estonia has been combatting African swine fever (ASF) for six years now. Since October 2017, the disease has only been detected in the wild boar population, but trade restrictions had to remain in place due to international regulations. Yet, the epidemiological course of [...] Read more.
Estonia has been combatting African swine fever (ASF) for six years now. Since October 2017, the disease has only been detected in the wild boar population, but trade restrictions had to remain in place due to international regulations. Yet, the epidemiological course of the disease has changed within the last few years. The prevalence of ASF virus (ASFV)-positive wild boar decreased steadily towards 0%. In February 2019, the last ASFV-positive wild boar was detected. Since then, positive wild boar samples have exclusively been positive for ASFV-specific antibodies, suggesting the possible absence of circulating ASFV in the Estonian wild boar population. However, as the role of seropositive animals is controversially discussed and the presence of antibody-carriers is regarded as an indication of virus circulation at EU and OIE level, Estonia remains under trade restrictions. To make the disease status of a country reliable for trading partners and to facilitate the process of declaration of disease freedom, we suggest to monitor the prevalence of seropositive wild boar in absence of ASFV-positive animals. The possibility to include ASF in the list of diseases, for which an official pathway for recognition of disease status is defined by the OIE should be evaluated. Full article
(This article belongs to the Special Issue African Swine Fever Virus Prevention and Control)
Show Figures

Figure 1

Open AccessArticle
Deletion of the Gene for the Type I Interferon Inhibitor I329L from the Attenuated African Swine Fever Virus OURT88/3 Strain Reduces Protection Induced in Pigs
Vaccines 2020, 8(2), 262; https://doi.org/10.3390/vaccines8020262 - 30 May 2020
Abstract
Live attenuated vaccines are considered to be the fastest route to the development of a safe and efficacious African swine fever (ASF) vaccine. Infection with the naturally attenuated OURT88/3 strain induces protection against challenge with virulent isolates from the same or closely related [...] Read more.
Live attenuated vaccines are considered to be the fastest route to the development of a safe and efficacious African swine fever (ASF) vaccine. Infection with the naturally attenuated OURT88/3 strain induces protection against challenge with virulent isolates from the same or closely related genotypes. However, adverse clinical signs following immunisation have been observed. Here, we attempted to increase the OURT88/3 safety profile by deleting I329L, a gene previously shown to inhibit the host innate immune response. The resulting virus, OURT88/3ΔI329L, was tested in vitro to evaluate the replication and expression of type I interferon (IFN) and in vivo by immunisation and lethal challenge experiments in pigs. No differences were observed regarding replication; however, increased amounts of both IFN-β and IFN-α were observed in macrophages infected with the deletion mutant virus. Unexpectedly, the deletion of I329L markedly reduced protection against challenge with the virulent OURT88/1 isolate. This was associated with a decrease in both antibody levels against VP72 and the number of IFN-γ-producing cells in the blood of non-protected animals. Furthermore, a significant increase in IL-10 levels in serum was observed in pigs immunised with OURT88/3ΔI329L following challenge. Interestingly, the deletion of the I329L gene failed to attenuate the virulent Georgia/2007 isolate. Full article
(This article belongs to the Special Issue African Swine Fever Virus Prevention and Control)
Show Figures

Figure 1

Open AccessArticle
A Pool of Eight Virally Vectored African Swine Fever Antigens Protect Pigs against Fatal Disease
Vaccines 2020, 8(2), 234; https://doi.org/10.3390/vaccines8020234 - 18 May 2020
Cited by 2
Abstract
Classical approaches to African swine fever virus (ASFV) vaccine development have not been successful; inactivated virus does not provide protection and use of live attenuated viruses generated by passage in tissue culture had a poor safety profile. Current African swine fever (ASF) vaccine [...] Read more.
Classical approaches to African swine fever virus (ASFV) vaccine development have not been successful; inactivated virus does not provide protection and use of live attenuated viruses generated by passage in tissue culture had a poor safety profile. Current African swine fever (ASF) vaccine research focuses on the development of modified live viruses by targeted gene deletion or subunit vaccines. The latter approach would be differentiation of vaccinated from infected animals (DIVA)-compliant, but information on which viral proteins to include in a subunit vaccine is lacking. Our previous work used DNA-prime/vaccinia-virus boost to screen 40 ASFV genes for immunogenicity, however this immunization regime did not protect animals after challenge. Here we describe the induction of both antigen and ASFV-specific antibody and cellular immune responses by different viral-vectored pools of antigens selected based on their immunogenicity in pigs. Immunization with one of these pools, comprising eight viral-vectored ASFV genes, protected 100% of pigs from fatal disease after challenge with a normally lethal dose of virulent ASFV. This data provide the basis for the further development of a subunit vaccine against this devastating disease. Full article
(This article belongs to the Special Issue African Swine Fever Virus Prevention and Control)
Show Figures

Figure 1

Review

Jump to: Research

Open AccessReview
The African Swine Fever Virus (ASFV) Topoisomerase II as a Target for Viral Prevention and Control
Vaccines 2020, 8(2), 312; https://doi.org/10.3390/vaccines8020312 - 17 Jun 2020
Abstract
African swine fever (ASF) is, once more, spreading throughout the world. After its recent reintroduction in Georgia, it quickly reached many neighboring countries in Eastern Europe. It was also detected in Asia, infecting China, the world’s biggest pig producer, and spreading to many [...] Read more.
African swine fever (ASF) is, once more, spreading throughout the world. After its recent reintroduction in Georgia, it quickly reached many neighboring countries in Eastern Europe. It was also detected in Asia, infecting China, the world’s biggest pig producer, and spreading to many of the surrounding countries. Without any vaccine or effective treatment currently available, new strategies for the control of the disease are mandatory. Its etiological agent, the African swine fever virus (ASFV), has been shown to code for a type II DNA topoisomerase. These are enzymes capable of modulating the topology of DNA molecules, known to be essential in unicellular and multicellular organisms, and constitute targets in antibacterial and anti-cancer treatments. In this review, we summarize most of what is known about this viral enzyme, pP1192R, and discuss about its possible role(s) during infection. Given the essential role of type II topoisomerases in cells, the data so far suggest that pP1192R is likely to be equally essential for the virus and thus a promising target for the elaboration of a replication-defective virus, which could provide the basis for an effective vaccine. Furthermore, the use of inhibitors could be considered to control the spread of the infection during outbreaks and therefore limit the spreading of the disease. Full article
(This article belongs to the Special Issue African Swine Fever Virus Prevention and Control)
Show Figures

Figure 1

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: Preventing African swine fever with or without a vaccine – complementary and alternative approaches in free-ranging pig populations and backyard farming systems
Authors: Mary Louise
Affiliation: 1 Department of Veterinary Tropical Diseases, University of Pretoria, South Africa 2 TAD Scientific CC, Menlo Park, South Africa
Abstract: The spectacular recent spread of African swine fever in Eastern Europe and Asia has been strongly associated, as it is in the endemic areas in Africa, with free-ranging wild, feral and domestic pig populations and low-biosecurity, mainly backyard pig farming. Managing the disease in wild populations and in circumstances where the disease is largely driven by poverty is particularly challenging and may remain so even in the presence of an efficacious vaccine. In the absence of vaccination, the only option currently available to prevent ASF is strict biosecurity. Among small-scale to family level pig farmers, biosecurity measures are often considered to be unaffordable both by the farmers and the government veterinary services. However, as outbreaks of ASF are also unaffordable, the adoption of at least basic biosecurity measures is imperative, and many of these depend on behaviour rather than money. A longer-term approach that could prove valuable particularly for free-ranging suid populations would be exploitation of innate resistance to the pathogenic effects of the virus, which is fully effective in wild African suids and has been observed in some domestic pig populations in long-time endemic areas. We explore the available options for preventing ASF in terms of feasibility, practicality and affordability among suid populations that are most at risk both of being decimated by ASF and of becoming a permanent source of infection for the global pig population.

Back to TopTop