Unraveling VP2 mutations in Infectious Bursal Disease Virus (IBDV) associated with potential vaccine escape in poultry flocks in Shandong, China
Bibliographic record
Abstract
BACKGROUND: Infectious bursal disease virus (IBDV) remains a major threat to the global poultry industry, causing significant economic losses. Recent surveillance data indicate that genetically diverse strains of IBDV are circulating in different regions of China. METHODS: In this study, both commercial and backyard chicken flocks from Shandong Province were investigated for evidence of IBDV circulation using a combination of serological assays and molecular detection techniques. RESULTS: Despite routine vaccination, antibody responses were highly variable, with some flocks showing reduced maternal immunity while others exhibiting active seroconversion by 35 days of age. Many birds showed an abnormally low bursa-to-body weight ratio, with a significant decline observed between 18 and 35 days of age in most farms, indicating immunosuppression. RT-PCR detected IBDV in 68 bursal samples, most of which were classified as very virulent strains (vvIBDV) belonging to genogroup A3, while a smaller subset was identified as variant strains within genogroup A2 based on phylogenetic analysis of the VP2 gene. Comparison of the VP2 protein sequence with other Chinese strains revealed variations in key hypervariable region residues critical for antibody binding. Conserved markers of very virulent strains persisted, while the novel substitutions A222V and D279H emerged, neither of which is present in commonly used vaccine strains. CONCLUSIONS: Our findings highlight emerging IBDV variants with altered VP2 antigenicity, potentially causing vaccine escape and increasing poultry health and economic risks.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".