Med. Weter. 81
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| DOROTA ŻAKOWSKA , PATRYCJA WÓJCICKA, PATRYCJA GŁOWACKA |
| African Swine Fever – Current Challenges and Vaccine Development |
| African swine fever (ASF) is a highly contagious, incurable, and frequently fatal viral disease affecting domestic pigs of all breeds and ages, as well as wild boars. ASF is caused by a DNA virus of the genus Asfivirus within the family Asfarviridae. The etiological agent, African swine fever virus (ASFV), has an incubation period of approximately 4-8 days, depending on strain virulence. Acute ASFV infections are associated with mortality rates approaching 100%, whereas chronic infections, typically caused by less virulent strains, are characterized by intermittent fever, weight loss, persistent skin lesions, and arthritis. Currently, no highly effective antiviral therapies or safe and efficacious vaccines against ASF are available. Analyses of ASF vaccine research indicate that an effective vaccine must meet stringent criteria, including high safety, absence of clinical disease, minimal adverse effects, and prevention of viral shedding. In addition, such a vaccine should induce a robust and longlasting immune response, be cost-effective and easy to administer, and enable differentiation between vaccinated and naturally infected animals (DIVA; Differentiating Infected from Vaccinated Animals). Several factors, including the complex pathogenesis of the disease, the intricate structure of ASFV, and a limited understanding of viral virulence factors and protective immune mechanisms, hamper the development of an effective ASF vaccine. Immune responses to ASFV infection are not fully elucidated, and neutralizing antibodies generated following experimental infection do not consistently confer protection against reinfection or disease. Current vaccine strategies include inactivated, recombinant, and live attenuated vaccines. Live attenuated vaccines generally confer protection only against homologous strains of the same genotype and may induce adverse effects, chronic infections, or carry a risk of reversion to virulence. Moreover, their development is constrained by the lack of stable cell lines for virus propagation, in contrast to subunit, DNA, and vector-based vaccines, which do not require amplification of infectious virus in cell culture. The rational design of an effective ASFV vaccine should therefore aim to elicit both humoral and cellular immune responses to ensure comprehensive and durable protection. |
| Key words: African swine fever, live attenuated vaccine, inactivated vaccine, subunit vaccine. |