In the data set, we had 2 genetic lineages (Iran-96 and G-IV) that each contained 2 strains. neutralization test, neutralization index test, and liquid-phase blocking enzyme-linked immunosorbent assay (ELISA). The titers were then used to calculate relationship coefficient ((1). It has seven different serotypes, namely, O, A, C, Asia 1, and Southern African Territories (SAT) 1, 2, and 3, with multiple subtypes within each serotype (2). FMD virus (FMDV) is a highly variable RNA virus (3,C5), and in general, there is usually little or no cross-protection between serotypes and even between different strains of the same serotype (2, 6, 7). Serotype A is considered to be the most antigenically and genetically diverse of the FMDV serotypes, RG14620 and new antigenic variants emerge frequently (8, 9). An inactivated FMDV vaccine is being used to control FMD. This type of vaccine is commonly used in many parts of the world, namely, South America, Asia, and Africa, where FMD is usually endemic. Although the quality of the vaccine used is probably the most important factor for the success of a vaccination program, a reasonable antigenic match between the FMDV vaccine and the outbreak virus strains is also considered essential RG14620 for the effectiveness of the vaccine (6). Initially, cross-protection studies were performed to test for antigenic differences. However, since serological assessments became available, they are also being used for antigenic matching on the basis of the assumption/hypothesis that the level of protection is usually correlated with the antigenic match from the serological assessments. In such serological assessments, the antibody titers of serum samples collected from vaccinated animals against both the vaccine strain and field strain virus are decided (6, 10). The value that is used the most to express antigenic match is the relationship coefficient (= 10) strains that were isolated in Africa, the Middle East, and Europe were selected from various genetic lineages (Table 1). The 10 strains were A/KEN/12/2005, A/ERI/2/98, A/SUD/2/84, A/ETH/13/2005, and A/MAU/1/2006, which were received from the OIE/FAO World Reference Laboratory for FMD (The Pirbright Institute, United Kingdom), and A10/Holland/42, A22/IRQ/24/64, A/TUR/20/2006, A/TUR/14/98, and A/IRN/2/97, obtained from the Central Veterinary Institute (CVI) (Wageningen UR, Lelystad, The Netherlands). For a control on the strain identity, we sequenced the VP1 gene of the 10 FMDV serotype A strains and compared them to data in the NCBI database. TABLE 1 FMDV serotype A strains used in the study and test using Holm’s adjustment for multiple testing. A value of <0.05 was considered statistically significant. Statistical analyses were carried out using R version 2.14 (32). (iv) Receiver operating characteristic analysis. An ROC analysis was carried out to determine which serological technique and the RG14620 and innocuity assessments did not detect live FMDV in the BEI-inactivated antigens produced from these 10 strains. FMDV NS-ELISA. All sera collected at the start of the experiment were unfavorable in the Prionics NS-ELISA (28). In total, 7 cattle were positive in the NS-ELISA postvaccination, and in 4 of them only at one time point postvaccination (1, 3, or 4 w.p.v.), in 2 cattle at two time points, and in one cow at 2, 3, and 4 w.p.v. The maximum percent inhibition observed was 58%. Postvaccination antibody response. Serum samples RG14620 collected from all cattle at 1, 2, 3, and 4 w.p.v. were tested using VNT against the homologous vaccine test strain. In some cattle, a low reaction was detected in the VNT before vaccination (Fig. 1); this was also seen in the sera of the control animals, especially with test strain A10/Holland/42. All vaccinated cattle responded to vaccination, with an increase in the Mouse Monoclonal to E2 tag log10 antibody titer in the first week ranging from 0.3 (2-fold) to 3.0 (1,000-fold), with a median of 1 1.1. At 2 to 4 w.p.v., the increase was 0.6 (4-fold) compared to the log10 titer before vaccination, with a median increase of 2.1 log10. The mean 3-w.p.v. homologous log10 titer in the VNT ranged from 1.5 to 3.5 (Fig. 1). The mean VNT titer 3 w.p.v. against the homologous and 9 heterologous virus test strains used in the VNT in the different vaccine groups ranged from 1.6 for A/MAU/1/2006 to 2.0 for A/TUR/20/2006, with an overall mean titer of 1 1.8. Open in a separate window FIG 1 VNT homologous mean titers, including standard error of the mean values of FMDV serotype A strains postvaccination responses in cattle.