Evidence map›Paper›PMID 42291841›Full record

ArticleLancet regional health. Americas2026

Epidemiology and severity of pediatric influenza hospitalizations before and during the COVID-19 pandemic: a surveillance study of the Canadian immunization monitoring program (IMPACT), 2012-2023.

Costanza Di Chiara, Jesse Papenburg, Julie A Bettinger, Daniel S Farrar, Waison Wong, Catherine Burton, Scott A Halperin, Taj Jadavji, Kescha Kazmi, Manish Sadarangani and 2 more

Abstract read
In one paragraph

Article in Lancet regional health. Americas, 2026. 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

12 authors.

Costanza Di ChiaraDivision of Infectious Diseases, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
Jesse PapenburgDivision of Infectious Diseases, Montreal Children's Hospital, McGill University Health Centre, 1001 Décarie Blvd, Montreal, QC, H4A 0B1, Canada.
Julie A BettingerVaccine Evaluation Center, BC Children's Hospital Research Institute, 950 West 28th, Vancouver, BC, V5Z 4H4, Canada.
Daniel S FarrarChild Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, 686 Bay St., Toronto, ON, M5G 0A4, Canada.
Waison WongDepartment of Pediatric Infectious Diseases & Immunology, Alder Hey Children's Hospital, Liverpool, UK.
Catherine BurtonDivision of Pediatric Infectious Diseases, Department of Paediatrics, Stollery Children's Hospital, University of Alberta, 8440 112 St NW, Edmonton, AB, T6G 2B7, Canada.
Scott A HalperinCanadian Center for Vaccinology, Dalhousie University, IWK Health Center, 5850/5980 University Avenue, Halifax, NS, B3K 6R8 Canada.
Taj JadavjiAlberta Children's Hospital, University of Calgary, Pediatric Infectious Diseases, 28 Oki Drive NW, Calgary, AB, T3B 6A8, Canada.
Kescha KazmiDivision of Infectious Diseases, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
Manish SadaranganiVaccine Evaluation Center, BC Children's Hospital Research Institute, 950 West 28th, Vancouver, BC, V5Z 4H4, Canada.
Shaun K MorrisDivision of Infectious Diseases, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
Canadian Immunization Monitoring Program Active (IMPACT) Investigators

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: The COVID-19 pandemic disrupted respiratory virus circulation, including influenza. We described trends in seasonality, demographics, and severity of pediatric influenza hospitalizations in Canada before and during the pandemic. Methods: We conducted national prospective surveillance through the Canadian Immunization Monitoring Program, ACTive (IMPACT), across 12 tertiary-care pediatric centers. Children <17 years hospitalized with laboratory-confirmed influenza between August 2012-August 2023 were included. Periods were categorized as pre-pandemic (2012-March 2020), and pandemic (2021-2022, 2022-2023). Severe disease was defined as intensive care unit (ICU) admission, mechanical ventilation, extracorporeal membrane oxygenation, and/or death. Adjusted odds ratios (aOR) were estimated using multivariable logistic regression. Findings: Among 10,091 hospitalizations, 7938 occurred pre-pandemic (annual average = 955), 335 in 2021-2022, and 1810 in 2022-2023. The median age was 3.0 (IQR 1.2-6.4) in pre-pandemic, 3.3 (IQR 1.4-7.3) in 2021-2022, and 3.8 years (IQR 1.7-7.2, p < 0.001) in 2022-2023. ICU admissions declined in 2021-2022 (11.3%) and rose in 2022-2023 (15.9%), though remaining below pre-pandemic levels (17.3%). Mortality was stable across periods (0.6%). The odds of severe disease were lower in 2021-2022 (aOR 0.63, 95% CI 0.44-0.89) and 2022-2023 (aOR 0.85, 95% CI 0.74-0.98) compared to pre-pandemic. Interpretation: Pediatric influenza hospitalizations nearly doubled in 2022-2023, with a modest shift in age distribution toward older children. Although severity indicators rose compared to 2021-2022, they remained slightly reduced compared to pre-pandemic seasons, suggesting suggest a partial return toward pre-pandemic epidemiologic patterns. Funding: IMPACT is managed by the Canadian Paediatric Society and conducted on behalf of the Public Health Agency of Canada.

Indexed as

COVID-19 pandemicInfluenza epidemiologyInfluenza hospitalizationInfluenza severityPediatric populationSurveillance

Identifiers

PMID42291841
PMCPMC13264334

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.