Document Type : Original Article


1 Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran

2 Razi Vaccine Resaerch Institute

3 Department of Basic Sciences, School of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran.


Despite widespread vaccination against foot-and-mouth disease (FMD), many outbreaks still occur in endemic areas. We attempted to determine the genetic and antigenic properties of the O/PanasiaII/Qom-15 FMDV new vaccine strain. Thus, whole-genome sequencing was used to identify vulnerable pinpoint sites across the genome. Then the VP1 sequence (1D gene) of the O/PanasiaII/Qom-15 viral genome was compared to the VP1 sequences of two previously used vaccine strains, O/Panasia (JQ321837) and O/PanasiaII (JN676146). Finally, the antigenic relationship of these three viruses was calculated by the 2D-VNT test. At the nucleotide level, 47 single variants were identified, of which 19% were in the 5' UTR region, 79% in the polyprotein region, and 2% in the 3' UTR region. Approximately half of the SNPs that have occurred in the 1D gene result in amino acid substitutions in the VP1 structure. SNPs caused amino acid substitutions in other structural proteins, including VP2 and VP3, and some non-structural proteins (Lpro, 2C, and 3A). O/PanasiaII/Qom-15 shared higher sequence similarity with O/PanasiaII (91%) compared to O/Panasia (87.3%). Evaluating the r-value showed that the antigenic relationship of OpanasiaII/Qom-15 with the O/PanasiaII (29%) was greater than that of the O/Panasia (24%); however, all three viruses were immunologically distinct. Over ten years, the alteration of virus antigenicity and the lack of detectable adaptive pressure on the VP1 sequence suggests that studying genetic dynamics beyond the VP1 region is necessary to evaluate FMDV pathogenicity and vaccine ineffectiveness.


Main Subjects