Immunological properties of attenuated variants of African swine fever virus isolated in the Russian Federation

The paper presents the results of adaptation of the African swine fever (ASF) virus strain Stavropol to continuous cell cultures of homologous (A₄C₂, A₄C₂/9k, PSGK-60, and PPK-66b) and heterologous (CV-1) origin in which the virus accumulated at titers of respectively 5.0–6.5 and 4.0–4.5 logHAU₅₀/cm³. In this case, the African swine fever virus (ASFV) multiplied in the A₄C₂ and A₄C₂/9k cell cultures with manifestation of specific hemadsorption with pig erythrocytes. The ASFV culture variants of passages 24 and 33 in the A₄C₂/9k and passage 20 in the CV-1 cell cultures lost pathogenicity for pigs but didn’t protect them from death after challenged with a virulent virus.