Miklukho-Maklaya, Moscow, 117198 Russia, e-mail vvm-39@mail.ru Acknowledgements: Supported by Russian Science Foundation (the research project «Design of African swine fever virus candidate vaccine based on chimeric viruses», contract No 16-16-00090) Received August 29, 2016 A b s t r a c t The capability of causing haemadsorption at African swine fever (ASF) virus (ASFV) reproduction in swine bone marrow cell cultures, leukocytes or continuous cells in the presence of swine erythrocytes is characteristic of the majority of the virus isolates (W.A. Malmquist, D. Hay, 1960). <...> This trait is used for ASF diagnosis based on autohaemadsorption in porcine blood, the virus titration in cell culture, and selection of its attenuated variants in vitro (A.D. Sereda et al., 2014). <...> The heterogeneity of an ASFV population for quantitative haemadsorption characteristic (like «dense», «moderate» or «loose») is a phenotypic trait of ASFV isolates, strains and/or variants (V. Makarov et al., 2016). <...> Also, the proportion of the circumference of red blood cells as observed at their contact with infected macrophages serves as another quantifiable feature of haemadsorption. <...> Some quantitative differences in HIA activity levels of swine blood sera are determined in the assays carried out using virulent reference variants and their attenuated derivatives, and the obtained results require some interpretation. <...> Hence, as a rule, attenuated ASFV variants are prepared through a selection by limiting dilution from populations of virulent isolates of the virus clones that are characterized by a reduced potential to induce haemadsorption (D.V. Kolbasov et al., 2014). <...> Virions do not play a significant role in the mechanism of haemadsorption, nevertheless, their interaction with erythrocyte membranes promotes the virus dissemination throughout the swine organism and more effective introduction into the gut cells of ticks (L.K. Dixon et al., 2004). <...> ASFV haemadsorbing potentiality is determined by highly glycosylated transmembrane protein CD2v (J.M. Rodrнguez et al., 1993). <...> Probably, nonhaemadsorbing avirulent isolates emerge as a result of some shift of the open reading frames for EP402R and EP153R encoding the CD2v and lectin-like proteins, respectively (D.A. Chapman et al., 2008). <...> An assumption is made that the haemadsorption phenomenon is <...>