Evaluation of swine protection with foot-and-mouth disease O1/Campos and O/Primorsky/2014 vaccines against the O Mya-98 lineage virus from East Asia.

Two type O commercial vaccines, the O1/Campos and O/Primorsky/2014 vaccines, were studied to evaluate the in vivo efficacy in pigs against heterologous virus challenge with the O/SKR/Jincheon/2014 virus (O/SEA/Mya-98 lineage) isolated in Korea in 2014. The in vivo challenge results indicated that both vaccines induced a high heterologous virus neutralization test (VNT) titer by a single injection and successfully protected specific pathogen-free (SPF) pigs from challenge infection. To determine the optimal vaccination age, a field trial with each vaccine was conducted with three one-shot-vaccinated groups that were injected at 8, 12, or 14 weeks of age and one two-shot-vaccinated group that was injected at 8 and 12 weeks of age in the pig farms. In these field trials, the improved serological performance at 20 and 24 weeks of age expected with vaccination at 12 or 14 weeks of age was not observed, although improved serological results were expected as the result of decreasing interference of maternally derived antibodies (MDAs), as MDAs waned with age. In addition, delayed vaccination resulted in MDA depletion at 14 weeks of age. Therefore, the optimal age for primary vaccination with two different formulated vaccines was 8 weeks old in pigs, considering that MDAs could provide a protective immunity against foot-and-mouth disease (FMD) infection. Prolonged significantly higher VNT titers of immunized pigs were demonstrated in the two-shot-vaccinated groups. In total, the effectiveness of the two vaccines was demonstrated through efficacy tests and field trials in pigs.

The interference effect of maternally-derived antibodies on the serological performance of pigs immunized with a foot-and-mouth disease oil emulsion vaccine.

To control foot-and-mouth disease (FMD) outbreaks that originated in Jincheon County in South Korea between 2014 and 2015, several commercial vaccines were studied for their efficacy and serological performance in the field. In this study, the efficacy of the O SKR 7/10 vaccine was evaluated by challenge with the FMD virus (FMDV) O/Jincheon/SKR/2014 (O Jincheon), which has the same O/SEA/Mya-98 lineage as the O/SKR/7/10 strain that was isolated in 2010 in South Korea, in FMD-seronegative pigs. Full protection against the O Jincheon virus was demonstrated as early as 14 days postvaccination, which was explained by the strong serological relationship (r1 value: ≥ 0.92) between the O Jincheon and O SKR 2010 viruses. However, in the field trial, no satisfactory serological elevations against FMDV were observed, even in the double-vaccinated groups. Therefore, it can be concluded that the O SKR 7/10 vaccine may need to be improved to overcome the interference effects from the high levels of maternally-derived antibodies generated due to the mandatory nationwide vaccination of sows in South Korea.

Cross-protective efficacy of the O1 Manisa + O 3039 bivalent vaccine and the O 3039 monovalent vaccine against heterologous challenge with FMDV O/Jincheon/SKR/2014 in pig.

After massive foot-and-mouth disease (FMD) outbreaks originated from Jincheon County from Dec. 2014 to Apr. 2015, the effectiveness of the previous FMD vaccine containing only the O1 Manisa as the O antigen, O1 Manisa + A Malaysia 97 + Asia 1 Sharmir trivalent vaccine, was questioned in South Korea, and a change in the O antigen in FMD vaccines was demanded to control the FMD caused by FMDV O/Jincheon/SKR/2014, the O Jincheon strain. Therefore, the efficacies of O1 Manisa + O 3039 bivalent vaccine and O 3039 monovalent vaccine were studied for cross-protection against heterologous challenge with the O Jincheon strain. In this study, the efficacy of the O1 Manisa + O 3039 bivalent vaccine was better than that of the O 3039 monovalent vaccine, even though the serological relationship (r1 value) between O Jincheon and O 3039 was matched according to the OIE Terrestrial Manual. According to serological test results from vaccinated specific pathogen free pigs, virus neutralization test titers against Jincheon were good estimates for predicting protection against challenge. A field trial of the O1 Manisa + O 3039 bivalent vaccine was performed to estimate the possibility of field application in conventional pig farms, especially due to concerns about the effect of maternally derived antibodies (MDA) in field application of the FMD vaccine. According to the result of the field trial, the O1 Manisa + O 3039 bivalent vaccine was considered to overcome MDA. The results of the efficacy and field trials indicated that the O1 Manisa + O3039 vaccine could be suitable to replace previous FMD vaccines to control the FMD field situation caused by O Jincheon FMDV.

Financial Impact of Foot-and-mouth disease outbreaks on pig farms in the Republic of Korea, 2014/2015.

The financial impact of foot-and-mouth disease (FMD) that occurred in 180 piggeries (100 farrow-to-finish and 80 fattening farms) confirmed infected during the 2014/2015 epidemic in the Republic of Korea was estimated at the farm level. The median loss due to slaughtering of pigs prior to their expected market weights was US$ 71.8 (uncovered compensation-compensation loss) plus US$ 57.3 (foregone net gain) per pig. Median loss per farm was US$ 27,487 (55.6% of total loss) for compensation and US$ 15,925 (44.4%) for foregone net gain. The total loss per farm (median, 25th-75th percentile) was US$ 43,822 (9,767-115,893), which represented 49.4% (11.5-112.8) of the annual net gain of pig farms. The total financial loss in 180 FMD outbreak pig farms was US$ 25.2 million, which was nearly one-half of the control cost (US$ 58.3 million) spent by the Korean government on this epidemic. The findings in this study should help planning to help reduce the impact at the farm level in the Republic of Korea in the future.

Generation of anti-proteinase 3 monoclonal antibodies and development of immunological methods to detect endogenous proteinase 3.

Proteinase 3 (PR3), a neutrophil granule serine protease, is the major autoantigen for autoantibodies in the systemic vasculitic disease, Wegener's granulomatosis. It is also found to be involved in various inflammatory diseases including Crohn's disease, rheumatoid arthritis, cystic fibrosis, and gingivitis. However, there is no high quality antibody available to detect endogenous PR3 in biological samples such as plasma and tissue. Several commercial anti-PR3 monoclonal antibodies (MAbs) were obtained by using HMC-1/PR3 cell granule extracts as the antigen, but the resulting antibodies could not be applied for immunoblotting or other immunological methods. Therefore, we produced human recombinant PR3 in Escherichia coli and developed several MAbs that are highly sensitive and can be used for immunoblotting, FACS analysis, and immunofluorescent staining. The PR3 MAbs recognized both rhPR3 and human plasma-derived neutrophil PR3 in reducing and non-reducing conditions at low nanogram levels. In addition, new MAbs detect endogenous PR3 from normal human plasma and urine with high specificity. The new anti-PR3 MAbs will be an essential tool for investigating the role of PR3 in inflammatory and autoimmune diseases.