Safety and Immunogenicity of a Pneumococcal Conjugate Vaccine When Administered Concomitantly With Routine Pediatric Vaccines in Healthy Toddlers and Infants
Bibliographic record
Abstract
BACKGROUND: A 21-valent pneumococcal conjugate vaccine, PCV21, was developed to provide broader coverage against Streptococcus pneumoniae serotypes. PCV21 comprises 13 serotypes common to a licensed 13-valent pneumococcal conjugate vaccine (PCV13) and 8 additional serotypes. This study evaluated 3 PCV21 formulations with differences in antigen content for some serotypes, compared with PCV13, administered concomitantly with routine pediatric vaccines. METHODS: This was a randomized, modified double-blind, multicenter, active-controlled phase 2 study enrolling toddlers previously vaccinated with 3 doses of PCV13 (cohort 1) and unvaccinated infants (cohort 2). Toddlers/infants were randomized 1:1:1:1 to 1 of 3 PCV21 formulations or PCV13, administered at ages 12-15 months (cohort 1) and 2, 4, 6 and 12-15 months (cohort 2). Safety was assessed throughout the study. Immunogenicity was assessed 30 days after dose 1 (cohort 1) or doses 3 and 4 (cohort 2). RESULTS: Overall, 140 toddlers (cohort 1) and 712 infants (cohort 2) were randomized. All PCV21 formulations showed acceptable safety profiles comparable with PCV13. In both cohorts, serotype-specific immunoglobulin G concentrations showed that PCV21 elicited a robust immune response for all serotypes. PCV21 and PCV13 showed generally comparable immunogenicity for shared serotypes, with numerically greater immunogenicity in the PCV21 groups than in the PCV13 group for the additional serotypes. Increased antigen content for selected serotypes appeared to be associated with greater immunogenicity. CONCLUSION: PCV21 demonstrated favorable immunogenicity, with no safety concerns identified. This study supports the evaluation of the PCV21 formulation that had the highest antigen content for selected serotypes for phase 3 assessment.
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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 | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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) | 0.000 | 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 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".