No abstract

Aim: To determine the minimal effective dose of Foot and Mouth disease (FMD) serotypes (A, O, SAT2) according to antigenic content (146S) in order to produce a potent trivalent FMD vaccine.Materials and Methods: Monovalent ISA 206 vaccines were prepared with 3 final concentration of 146S (1.6, 2.2, 2.8 µg/dose). The vaccine potency was evaluated by the determination of guinea pig protective dose 50 (GPPD )for each 50 concentration of 146S for each type of FMD monovalent vaccine where a fourfold dilution of the vaccines was constructed and each dilution was inoculated as 0.5 ml S/C in each of 5 guinea pigs. Results:The obtained results revealed that by using 1.6 µg of 146S for type O Pan Asia-2, A Iran O5 and SAT/EGY/2012, the GPPD was 40.4, 19.75 and 31.6 respectively, while the use of 2.2 µg of 146S resulted in GPPD 78.6, 78.6 and 105.8 for the 50 50 three types respectively, and by using 2.8 µg of 146S resulted in GPPD 161.7, 105.8 and 161.7 for the three subtypes (A, O, 50 SAT2) respectively. So it is clear that the lowest 146S dilution inducing good protection (more than 72 GPPD ) was 2.2 µg for 50 each serotype of used FMD monovalent vaccines. Depending on this result, the trivalent vaccine was formulated as 2.2 µg of 146S payload from each virus type/dose with equal volume of montanide ISA 206 oil as adjuvant. For more confirmation the prepared trivalent vaccine potency was evaluated by Guinea pig protective dose 50 which was found to be 88 GPPD .Also 50 mean SNT antibody titer was detected in serum of the test Guinea pigs 1.56, 1.68 and 1.68 log /ml against FMDV serotype O 10Pan Asia-2, A Iran O5 and SAT/EGY/2012 respectively in a higher level than the recommended protective titer (PT=1.2). Also for further confirmation the formulated trivalent vaccine which contain 2.2 µg/serotype/dose were evaluated in cattle to measure the antibody titer against the three serotypes and the antibody against the three serotypes were found to be higher than the recommended titer (1.5) which extended for 32 WPV and these results came in parallel manner to the GPPD and antibody 50 titer of the Guinea pigs of the prepared trivalent vaccine with 146S (2.2 µg/serotype/dose). Conclusion:It could be concluded that the minimum content of antigenic 146S of FMDV serotype O pan Asia, A Iran O5 and SAT2/EGY/2012 should not be less than 2.2 µg/dose/ from each serotype in the trivalent vaccine aiming to induce the permissible protection in vaccinated livestock.

Aim:This work was aimed to document the antiviral activates of Spirulina platensis extract against foot and mouth disease virus (FMDV) different types to evaluate its replication in Baby Hamster Kidney (BHK) cell culture and in baby mice.Materials and Methods:Cytotoxicity assay studied for S. platensis extract on BHK cells to determine the non-toxic dose. The non-toxic dose of Spirulina extract was mixed with each type of FMDV (A, O, SAT2). Then 10-fold dilutions from each mixture were done. FMDV titer for each type of treated FMDV was calculated to evaluate the antiviral activity of the Spirulina extract against FMDV. Furthermore, old baby Swiss mice were inoculated with 0.1 ml intraperitonially from the mixture of FMDV different types and different concentration of Spirulina extracts. After 48 h post inoculation, all the baby mice examined to evaluate the antiviral action of Spirulina extract.Results:The result showed that the non-toxic doses of S. platensis (50 ug/ml) revealed 35.7%, 28.5%, and 31% reductions in FMDV titers Type O, A, and SAT2 on BHK cells, respectively. The same non-toxic dose gave 50% of the inhibitory concentration in baby mice without cytotoxic effect.Conclusion:This study confirmed the biological activity of the ethanol extract of S. platensis against FMDV Types O, A, and SAT2. From the results, S. platensis could be useful as antiviral lead to limitation of infection among animals during outbreaks but further studies need to evaluate the S. platensis on experimental or natural infected farm animals to establish the effective dose side affected period of treatment of S. platensis.

No abstract

Nanotechnology plays a unique and novel role to develop new methods for adjuvant preparation, which play an important role in the efficacy of vaccines. In this study we have studied the effects of Calcium phosphate nanoparticles (CaP) <150 nm particle size measuring with Electron microscope, on the magnitude and type of immunity elicited in response to inactivated FMD trivalent vaccine. A comprehensive sero-immunological study was conduced to reveal the adjuvant's effect of Calcium phosphate nanoparticles on the immune response to oil adjuvanted trivalent Foot and Mouth Disease (FMD) in vaccinated calves. This study was conducted in three calve groups; group (A) vaccinated subcutaneously with trivalent oil FMD vaccine, group (B) vaccinated subcutaneously with trivalent FMD vaccine adjuvanted with Calcium Phosphate nonaoparticles (10 mg/dose).While group (C) vaccinated subcutaneously with trivalent FMD vaccine adjuvanted with both oil and CaP nanoparticles. The humeral and cellular immunoresponses were monitored in different tested groups. Results indicated that the incorporation of Calcium phosphate nanoparticles into inactivated FMD vaccine induces an increase of the specific protective immune response. Higher and longer period of immune responses were found in calves vaccinated with both oil and Calcium phosphate nanoparticles adjuvanted vaccine up to 40 week, while those vaccinated with Calcium Phosphate nanoparticles and with oil vaccine showed protected immunity up to 36 and 32 weeks respectively.