Novel P22-monoclonal antibody based blocking ELISA for the detection of African swine fever virus antibodies in serum

•Scientific question: African swine fever (ASF) is a highly infectious and fatal disease of pigs. Due to the complexity of the ASF virus (ASFV) and various clinical forms of the disease, a wide range of highly effective and robust sero-diagnostic assays are required.•Evidence before this study: The use of the most antigenic ASFV proteins is highly crucial to improving sero-diagnostic assays. Currently, only a few highly antigenic recombinant proteins have been tested and validated for use as reagents in ASF sero-diagnostic assays. So far, three ELISA kits based on the recombinant proteins P72, P30, and PP62 have been approved.•New findings: In this study, based on the recombinant P22 protein, a highly sensitive, specific, and rapid P22 monoclonal antibody-based blocking ELISA (mAb-bELISA) assay was developed to detect serum antibodies induced by genotype I and II ASFVs to detect ASFV antibodies. A total of 806 pig serum samples were tested to evaluate the performance of the diagnostic assay. The assay was able to detect ASFV antibodies as early as 9 days post-infection.•Significance of the study: Based on this study, the noval P22-mAb based bELISA assay can be used for rapid and accurate detection of antibodies against ASFV, which will play a valuable role in the containment and prevention of ASF as an alternative to other serological diagnostic methods. Also, this study will assist researchers to further investigate the immunogenic importance of the P22 protein in ASFV infection.