Molecular assay for detecting MS-H vaccine strain and Immune response mechanisms in chickens receiving one or two doses of live MS-H vaccine

This study aimed to verify the PCR-RFLP molecular assay as a convenient technique for detecting the MS-H vaccine strain and to characterize the immune response mechanisms in experimental layer-type chickens receiving three different vaccination programs; a single dose at either 9 or 12 weeks of age or two doses at both 9 and 12 weeks of age. The PCR-RFLP assay, using restriction enzyme TasI to digest vlhA gene-targeted PCR amplicons, was performed to evaluate vaccine administration by detecting the MS-H vaccine strain in vaccinated chickens and differentiating it from non-vaccine strains as WVU1853 reference strain and Thai M. synoviae field strains. Results demonstrated that vaccination in layer-type chickens, whether as one or two doses, stimulated immune response mechanisms with no significant advantages of two administrations over a single administration. Serological responses in vaccinated chickens, examined by RPA test and ELISA, were initially detected at 2 weeks post-vaccination, continuously increasing, and then maintaining at the baseline levels during 6 to 9 weeks post-vaccination. Cellular immune responses against both homologous and heterologous antigens, examined by the MTS tetrazolium assay, were similar in the early period post-vaccination, whereas cellular immune response against the homologous MS-H antigen was improved in the late period post-vaccination.PMID:37791564 | DOI:10.1080/03079457.2023.2267022
Source: Avian Pathology - Category: Pathology Authors: Source Type: research