Increased survival and reduced bacterial shedding following single but not repeated oral immunizations against <i>Piscirickettsia salmonis</i> in Atlantic salmon <i>Salmo salar</i>
Bibliographic record
Abstract
Outbreaks of Piscirickettsia salmonis in cultured salmon populations result in high mortality and high economic loss. An efficacious vaccine against this pathogen is highly desired; however there has been limited success in this regard. In the current study, Atlantic salmon (Salmo salar) smolts were vaccinated by single, double, or quadruple immunization with a commercial oral vaccine developed using a Chilean isolate of P. salmonis. Fish were then challenged by immersion with a Canadian isolate of P. salmonis. Significantly greater survival was observed 300 degree-days (DD) following single immunization (30.9 relative percent survival - RPS) and 370 DD following quadruple immunization (21.1 RPS). Increased survival in the former group was associated with reduced bacterial shedding, and in the latter group, with increased mean days-to-death. Bacterium-specific serum antibodies were not influenced by vaccination in any treatment. No protection was elicited following double immunization. The relatively low protection observed following oral immunizations may be related to antigenic heterogeneity between the isolates used in vaccine manufacture and laboratory challenge. The results of this study highlight the difficulties in production of an efficacious vaccine against P. salmonis.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".