Evidence map›Paper›PMID 42189540›Full record

SynthesisJAMA network open2026

High-Dose vs Standard-Dose Influenza Vaccines in Older Adults: A Meta-Analysis.

Kristoffer Grundtvig Skaarup, Mats C H Lassen, Kaveh Hosseini, Niklas Dyrby Johansen, Matthew M Loiacono, Rebecca C Harris, Sandrine I Samson, Arto A Palmu, Kevin McConeghy, Stefan Gravenstein and 5 more

Abstract readMeta-AnalysisSystematic Review
In one paragraph

Synthesis in JAMA network open, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

15 authors.

Kristoffer Grundtvig SkaarupDepartment of Cardiology, Copenhagen University Hospital-Herlev and Gentofte, Copenhagen, Denmark.
Mats C H LassenDepartment of Cardiology, Copenhagen University Hospital-Herlev and Gentofte, Copenhagen, Denmark.
Kaveh HosseiniDepartment of Cardiology, Copenhagen University Hospital-Herlev and Gentofte, Copenhagen, Denmark.
Niklas Dyrby JohansenDepartment of Cardiology, Copenhagen University Hospital-Herlev and Gentofte, Copenhagen, Denmark.
Matthew M LoiaconoSanofi SA, Morristown, New Jersey.
Rebecca C HarrisSanofi SA, Singapore, Singapore.
Sandrine I SamsonSanofi SA, Lyon, France.
Arto A PalmuFinnish Vaccine Research, Tampere, Finland.
Kevin McConeghyDepartment of Health Services, Policy & Practice, Brown University School of Public Health, Providence, Rhode Island.
Stefan GravensteinDepartment of Health Services, Policy & Practice, Brown University School of Public Health, Providence, Rhode Island.
Orly VardenyDepartment of Medicine, University of Minnesota, Minneapolis Veterans Affairs Health Care System, Minneapolis.
Brian ClaggettDivision of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Scott D SolomonDivision of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Federico Martinón-TorresTranslational Pediatrics and Infectious Diseases, Hospital Clínico Universitario de Santiago and University of Santiago de Compostela, Santiago de Compostela, Galicia, Spain.
Tor Biering-SørensenDepartment of Cardiology, Copenhagen University Hospital-Herlev and Gentofte, Copenhagen, Denmark.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Importance: High-dose inactivated influenza vaccine (HD-IIV) was developed to enhance immune responses in older adults and has demonstrated superior protection against laboratory-confirmed influenza (LCI) and severe outcomes vs standard-dose inactivated influenza vaccine (SD-IIV). A comprehensive meta-analysis of recent large-scale trials is warranted. Objective: To synthesize all evidence from randomized clinical trials comparing HD-IIV with SD-IIV for prevention of hospitalization events and mortality in older adults. Data Sources: Studies published between December 31, 2009, and September 15, 2025, on PubMed and Embase. Additional data were obtained from trial sponsors. Study Selection: Randomized clinical trials comparing HD-IIV with SD-IIV in older adults during at least 1 influenza season were eligible. Data Extraction and Synthesis: Two reviewers independently screened studies, extracted data, and assessed risk of bias according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guideline. Unpublished subgroup and outcome data were obtained to enable detailed analyses. Combined relative vaccine effectiveness (rVE) estimates were calculated with fixed-effects models, with sensitivity analyses using random-effects models. Main Outcomes and Measures: Hospitalizations for influenza, LCI, pneumonia or influenza, cardiorespiratory disease, and all causes and all-cause mortality. Primary analyses included adults 65 years or older, and secondary analyses included prespecified subgroups by age and cardiovascular disease. Results: Eight randomized clinical trials including 605 098 participants were identified, with 5 enrolling older adults from the general population (aged ≥65 years), 2 enrolling nursing home residents (aged ≥65 years), and 1 enrolling patients with cardiovascular disease. Compared with SD-IIV, HD-IIV was associated with significantly reduced hospitalizations for influenza (rVE, 38.5%; 95% CI, 26.5%-48.5%), LCI (rVE, 31.2%; 95% CI, 19.3%-41.4%), pneumonia or influenza (rVE, 11.5%; 95% CI, 5.9%-16.8%), cardiorespiratory disease (rVE, 7.5%; 95% CI, 4.7%-10.3%), and all causes (rVE, 3.3%; 95% CI, 1.8%-4.8%). Mortality did not differ significantly between groups (rVE, 0.9%; 95% CI, -2.1% to 3.8%). Results were overall consistent across subgroup and sensitivity analyses. Conclusions and Relevance: This meta-analysis provides a comprehensive synthesis of evidence from randomized clinical trials comparing HD-IIV with SD-IIV in older adults. HD-IIV was associated with improved protection against hospitalization outcomes, from LCI to all causes, but was not associated with improvement of all-cause mortality. These findings may inform decision-makers in developing vaccine recommendations and policies.

Indexed as

Influenza, HumanInfluenza VaccinesAgedAged, 80 and overFemaleHospitalizationHumansMaleRandomized Controlled Trials as TopicVaccine EfficacyVaccines, InactivatedInfluenza VaccinesVaccines, Inactivated

Identifiers

PMID42189540
PMCPMC13213526

What OpenQuestion holds

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LicenceCC BY-NC-ND
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.