Evidence map›Paper›PMID 41041150›Full record

ArticleOpen forum infectious diseases2025

Effectiveness of the 2023 Southern Hemisphere Influenza Vaccine Against Outpatient Influenza-Like Illness: A Multi-Country Test-Negative Design Study.

Annette K Regan, Radhika Gharpure, Monique Chilver, Nigel Stocks, Siobhan St George, Sibongile Walaza, Anne von Gottberg, Nicole Wolter, Cheryl Cohen, Aaron M Samuels and 6 more

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Open forum infectious diseases, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing 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

1 citing paper in PubMed.

  1. Article
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

16 authors.

Annette K ReganDepartment of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, California, USA.ORCID https://orcid.org/0000-0002-3879-6193
Radhika GharpureInfluenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.ORCID https://orcid.org/0000-0002-0702-5628
Monique ChilverThe Discipline of General Practice, The University of Adelaide, Adelaide, South Australia, Australia.ORCID https://orcid.org/0000-0001-6369-8483
Nigel StocksThe Discipline of General Practice, The University of Adelaide, Adelaide, South Australia, Australia.
Siobhan St GeorgePublic Health and Surveillance Branch, Interim Australian Centre for Disease Control, Australian Government Department of Health, Disability and Ageing, Canberra, Australian Capital Territory, Australia.
Sibongile WalazaCentre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.ORCID https://orcid.org/0000-0001-7588-2480
Anne von GottbergCentre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.ORCID https://orcid.org/0000-0002-0243-7455
Nicole WolterCentre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.ORCID https://orcid.org/0000-0002-9526-0133
Cheryl CohenCentre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa.ORCID https://orcid.org/0000-0003-0376-2302
Aaron M SamuelsInfluenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.ORCID https://orcid.org/0000-0002-8355-8186
Kriengkrai PrasertNakhon Phanom Provincial Hospital, Nai Mueang, Mueang Nakhon Phanom District, Nakhon Phanom, Thailand.
Prabda PraphasiriFaculty of Public Health, Kasetsart University, Chalermprakiat Sakon Nakhon Province Campus, Mueang Sakon Nakhon District, Sakon Nakhon, Thailand.
William W DavisInfluenza Program, Thailand Ministry of Public Health-U.S. Centers for Disease Control and Prevention Collaboration, Muang, Nonthaburi, Thailand.ORCID https://orcid.org/0000-0001-7062-9531
Chakrarat PittayawonganonInstitute of Preventive Medicine, Department of Disease Control, Ministry of Public Health, Muang, Nonthaburi, Thailand.
Sheena G SullivanDepartment of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, California, USA.
Eduardo Azziz-BaumgartnerInfluenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.ORCID https://orcid.org/0000-0002-0298-5814

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: Routine monitoring of seasonal influenza vaccine effectiveness (VE) across multiple countries is essential to understand the performance of seasonal vaccine programs. Methods: Using a test-negative study design, we estimated the effectiveness of the 2023 Southern Hemisphere formulation of the seasonal influenza vaccine in preventing outpatient medically attended influenza-like illness (ILI) in Australia, South Africa, and Thailand. Sentinel surveillance systems identified patients presenting with ILI who were tested by RT-PCR for influenza. VE was estimated as one minus the odds ratio comparing the vaccination status of test-positive cases and test-negative non-cases. Models adjusted for country, patients' age group, sex, underlying medical conditions, and calendar week of symptom onset. We assessed the duration of protection by modeling the effect of the interval between vaccination and symptom onset on influenza status. Results: About 2469 ILI outpatients were identified, including 966 (39%) test-positive cases and 1503 (61%) test-negative non-cases; 78% ( Conclusions: The 2023 Southern Hemisphere formulation of seasonal influenza vaccines offered protection against ILI in three countries, underscoring the public health benefits of seasonal influenza vaccination programs.

Indexed as

influenza vaccinepooled analysissurveillancetest-negative designvaccine effectiveness

Identifiers

PMID41041150
PMCPMC12484440

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

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.