Efficacy of a single oral dose of a live bivalent E. coli vaccine against post-weaning diarrhea due to F4 and F18-positive enterotoxigenic E. coli
Bibliographic record
Abstract
F4- and F18-positive enterotoxigenic E. coli strains (F4-ETEC and F18-ETEC) are important causes of post-weaning diarrhea (PWD) in pigs. F4 (antigenic variant ac) and F18 (ab and ac) fimbriae are major antigens that play an important role in the early stages of infection. Herein, the efficacy of a live oral vaccine consisting of two non-pathogenic E. coli strains, one F4ac- and one F18ac-positive, was evaluated using F4ac-ETEC and F18ab-ETEC challenge models. A randomized, masked, placebo-controlled, block design, parallel-group confirmatory study with two different vaccination-challenge intervals (7 and 21 days) was conducted for each challenge model. The vaccine was administered in one dose, to ≥18-day-old piglets via drinking water. Efficacy was assessed by evaluating diarrhea, clinical observations, weight gain and fecal shedding of F4-ETEC or F18-ETEC. Anti-F4 and anti-F18 immunoglobulins in blood were measured. The vaccination resulted in significant reductions in clinical PWD and fecal shedding of F4-ETEC and F18-ETEC after the 7- and 21-day-post-vaccination heterologous challenges, except for after the 21-day-post-vaccination F4-ETEC challenge, when the clinical PWD was too mild to demonstrate efficacy. A significant reduction of mortality and weight loss by vaccination were observed following the F18-ETEC challenge. The 7-day protection was associated with induction of anti-F4 and anti-F18 IgM, whereas the 21-day protection was mainly associated with anti-F4 and anti-F18 IgA. The 7-day onset and 21-day duration of protection induced by this vaccine administered once in drinking water to pigs of at least 18days of age were confirmed by protection against F4-ETEC and F18-ETEC, and induction of F4 and F18-specific immunity. Cross protection of the vaccine against F18ab-E. coli was demonstrated for both the 7- and 21-day F18-ETEC challenges.
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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.002 |
| 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".