Determination of non-structural protein level for Turkey foot-and-mouth disease vaccine antigens during in-process

Purpose@#The success of foot-and-mouth disease (FMD) serological serosurveillance greatly depends on the FMD vaccine which does not include any non-structural proteins (NSPs) of the FMD virus. Since pure FMD vaccines from NSPs are used with the FMD eradication programs using DIVA (Differentiating Infected from Vaccinated Animals) tests. Apart from the in-vivo test defined in the World Organisation for Animal Health, two different test kits were developed in-process NSP detection purposes. The first test kit was developed in 2010 and the second one has been very recently developed in 2019. @*Materials and Methods@#In this study, the level of NSP has been examined by first-chemiluminescent filtration assisted (FAL)-enzyme-linked immunosorbent assay (ELISA) based invitro, in-process test kit for Turkey FMD vaccine antigen samples. A total of 94 samples were used. The critical maximum acceptable levels of NSP were determined after purification stage of samples. @*Results@#As a maximum NSP level, 70 ng NSP for the polyethylene glycol concentrated samples and 30 ng NSP for the vaccine antigen mixture samples were accepted. A mini repeatability study was also performed. The correlation between the NSP, total protein, and 146S particul quantity of samples were analyzed. @*Conclusion@#As a conclusion, the chemiluminescent FAL-ELISA based test kit can be used for the NSP purity level determination of in-process samples.

Determination of non-structural protein level for Turkey foot-and-mouth disease vaccine antigens during in-process

Purpose@#The success of foot-and-mouth disease (FMD) serological serosurveillance greatly depends on the FMD vaccine which does not include any non-structural proteins (NSPs) of the FMD virus. Since pure FMD vaccines from NSPs are used with the FMD eradication programs using DIVA (Differentiating Infected from Vaccinated Animals) tests. Apart from the in-vivo test defined in the World Organisation for Animal Health, two different test kits were developed in-process NSP detection purposes. The first test kit was developed in 2010 and the second one has been very recently developed in 2019. @*Materials and Methods@#In this study, the level of NSP has been examined by first-chemiluminescent filtration assisted (FAL)-enzyme-linked immunosorbent assay (ELISA) based invitro, in-process test kit for Turkey FMD vaccine antigen samples. A total of 94 samples were used. The critical maximum acceptable levels of NSP were determined after purification stage of samples. @*Results@#As a maximum NSP level, 70 ng NSP for the polyethylene glycol concentrated samples and 30 ng NSP for the vaccine antigen mixture samples were accepted. A mini repeatability study was also performed. The correlation between the NSP, total protein, and 146S particul quantity of samples were analyzed. @*Conclusion@#As a conclusion, the chemiluminescent FAL-ELISA based test kit can be used for the NSP purity level determination of in-process samples.

Effect of simultaneous administration of foot-and-mouth disease (FMD) and anthrax vaccines on antibody response to FMD in sheep

PURPOSE: Foot-and-mouth disease (FMD) and anthrax are important diseases in sheep. Vaccination is a favorable strategy against both infections. Simultaneous administration of vaccines does generally not impede the immune responses of each other, although there are some exceptions, and it may help reduce the labor and costs of vaccination as well as distress on animals. Although oil adjuvant FMD vaccine has been tried with live anthrax vaccine in cattle, there are no reports on the simultaneous use of both vaccines in sheep. MATERIALS AND METHODS: In this study, FMD seronegative sheep were used to investigate the impact of the simultaneous vaccination of FMD and anthrax on FMD antibody titers of sheep. Virus neutralization test and liquid phase blocking enzyme-linked immunosorbent assay were used to determine the antibody response to the FMD vaccine. RESULTS: The results demonstrated that both vaccines can be used simultaneously without any interference with the FMD response. Moreover, the simultaneous administration with anthrax vaccine had a stimulating effect on the early (day 7 post-vaccination) virus neutralization antibody response to the FMD vaccine. CONCLUSION: The simultaneous use of the FMD and anthrax vaccines did not hinder the response to the FMD vaccine in sheep.

Influence of vaccine potency and booster administration of foot-and-mouth disease vaccines on the antibody response in calves with maternal antibodies

Foot-and-mouth disease is one of the most important viral diseases of cloven-hoofed animals. Mass vaccination is an effective method to control the disease and is frequently utilized in endemic regions. Sufficient protection of young animals is important in mass vaccination campaigns. Maternal antibodies negatively affect the success of vaccination. Hence, determination of the optimal vaccination age is crucial for the uninterrupted protection of young animals. This study was performed to identify the effect of vaccine potency and booster administration on serum neutralizing antibody titers of calves with different levels of maternal antibodies. Calves (n = 111) on a state farm were used in this study. Oil adjuvant foot-and-mouth disease vaccines with 3 PD₅₀ and 6 PD₅₀ potencies were used with or without booster administration. Serum samples were collected each month up to day 120 postvaccination. Virus neutralization tests were used to measure the serum neutralizing antibody titers and estimate the protection period by using pre-determined cut-off values for protection. The results revealed that a vaccination with a 6 PD₅₀ potency vaccine, preferably followed by a booster dose, should be used to overcome maternal immunity for incessant protection.

QS-21 enhances the early antibody response to oil adjuvant foot-and-mouth disease vaccine in cattle

PURPOSE: One of the most important tools against foot-and-mouth disease, a highly contagious and variable viral disease of cloven-hoofed animals, is vaccination. However, the effectiveness of foot-and-mouth disease vaccines on slowing the spread of the disease is questionable. In contrast, high potency vaccines providing early protection may solve issues with the spread of the disease, escaping mutants, and persistency. To increase the potency of the vaccine, additives such as saponin and aluminium hydroxide are used. However, the use of saponin with an oil adjuvant is not common and is sometimes linked to toxicity. QS-21, which is less toxic than Quil A, has been presented as an alternative for use with saponin. In this study, the addition of QS-21 to a commercially available foot-and-mouth disease water-in-oil-in-water emulsion vaccine was evaluated in cattle. MATERIALS AND METHODS: After vaccination, serum samples were collected periodically over 3 months. Sera of the QS-21 and normal oil vaccine groups were compared via serum virus neutralization antibody titre and liquid phase blocking enzyme-linked immunosorbent assay antibody titre. RESULTS: The results showed that there was a significant early antibody increase in the QS-21 group. CONCLUSION: Strong early virus neutralizing antibody response will be useful for emergency or ring vaccinations against foot-and-mouth disease in target animals.