Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/7/2003
Publication Date: 2/20/2004
Citation: Neilan, J.G., Zsak, L., Lu, Z., Burrage, T.G., Kutish, G.F., Rock, D.L. 2004. Neutralizing antibodies to african swine fever virus proteins p30, p54 and p72 are not sufficient for antibody-mediated protection. Virology. 319(2):337-342. Interpretive Summary: It has been claimed by others that neutralizing antibodies to African swine fever virus (ASFV) proteins, p30 and p54, are associated with a protective immune response in swine. The data here does not support this claim. Currently, there is no vaccine for this disease and efforts to develop one has been hampered by the lack of knowledge regarding protective antigens. These data highlights the inability of neutralizing antibodies to confer solid protection to ASFV infection and suggests other mechanisms of protective immunity should be investigated.
Technical Abstract: Although antibody-mediated immune mechanisms have been shown to be important in immunity to ASF, it remains unclear what role virus neutralizing antibodies play in the protective response. Virus neutralizing epitopes have been identified on three viral proteins, p30, p54 and p72. To evaluate the role(s) of these proteins in protective immunity, pigs were immunized with baculovirus expressed p30, p54, p72 and p22, from the pathogenic ASFV isolate Pr4. ASFV specific neutralizing antibodies were detected in test group animals. Folowing immunization animals were challenged with 104 TCID50 of Pr4 virus. In comparison to the control group, test group animals exhibited a 2 day delay to onset of clinical disease and reduced viremia levels at 2 DPI, however, by 4 DPI there was no significant difference between the two groups and all animals in both groups died between 7 and 10 DPI. These results indicate that neutralizing antibodies to these ASFV proteins are not sufficient for antibody-mediated protection.