High-Dose Versus Standard-Dose Influenza Vaccine and Cardiovascular Outcomes in Older Adults: The FLUNITY-HD Prespecified Pooled Analysis
Bibliographic record
Abstract
BACKGROUND: The high-dose inactivated influenza vaccine (HD-IIV) has demonstrated superior protection against a range of hospitalization end points versus standard-dose inactivated influenza vaccine (SD-IIV), but its effectiveness against specific cardiovascular outcomes and in those with pre-existing cardiovascular disease (CVD) is not well elucidated. METHODS: In a prespecified secondary analysis of the FLUNITY-HD (Pooled Analysis of Methodologically Harmonized Pragmatic Randomized Trials of High-Dose vs. Standard-Dose Influenza Vaccine Against Severe Clinical Outcomes) individual-level pooled data set integrating 2 methodologically harmonized pragmatic, individually randomized trials conducted in Denmark and Spain, we investigated the relative vaccine effectiveness of HD-IIV versus SD-IIV against severe cardiovascular outcomes and according to pre-existing CVD among adults ≥65 years of age. Data were primarily obtained from routine health care databases, with follow-up from 14 days after vaccination to May 31 the following year. RESULTS: The pooled data set encompassed 466 320 individually randomized participants, of whom 107 700 (23.1%) had a history of CVD. HD-IIV reduced the incidence of hospitalization for influenza or pneumonia, cardiorespiratory disease, laboratory-confirmed influenza, and any cause compared with SD-IIV, irrespective of the presence or absence of pre-existing CVD ( P interaction >0.66 for all outcomes). Compared with the SD-IIV group, the HD-IIV group had a significantly lower incidence of hospitalization for any CVD (HD-IIV, 1.15%, versus SD-IIV, 1.24%; relative vaccine effectiveness, 6.6% [95% CI, 1.6–11.4]; P =0.010), hospitalization for any respiratory disease (HD-IIV, 0.92%, versus SD-IIV, 0.98%; relative vaccine effectiveness, 6.5% [95% CI, 0.7–11.9]; P =0.027), and hospitalization for heart failure (HD-IIV, 0.11%, versus SD-IIV, 0.15%; relative vaccine effectiveness, 21.3% [95% CI, 7.6–33.0]; P =0.003). CONCLUSIONS: In a prespecified pooled analysis of 466 320 individually randomized older adults, HD-IIV reduced the incidence of a wide range of severe cardiovascular and respiratory outcomes compared with SD-IIV, with consistent findings regardless of previous history of CVD. Among cardiovascular outcomes, the protective effect of HD-IIV versus SD-IIV was particularly pronounced against hospitalization for heart failure. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT06506812.
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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 | 0.042 | 0.048 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.012 | 0.039 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".