Observational studyPLoS pathogens2021
Induction of trained immunity by influenza vaccination - impact on COVID-19.
Observational study in PLoS pathogens, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT06341374 (Impact of Sleep Disorders on Innate Immunity in COVID-19 Patients. A Cohort Study), which is not on this map. Cited by 111 papers, 4 of them syntheses that pooled 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.
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.
Impact of Sleep Disorders on Innate Immunity in COVID-19 Patients. A Cohort Study
Who cites it
111 citing papers in PubMed, 4 syntheses or guidelines pooled it, 174 citations in OpenAlex.
- Vaccination against influenza viruses reduces infection, not hospitalization or death, from respiratory COVID-19: A systematic review and meta-analysis.Journal of medical virology · 2024Pooled it
- Evaluation of the efficacy, safety and influencing factors of concomitant and sequential administration of viral respiratory infectious disease vaccines: a systematic review and meta-analysis.Frontiers in immunology · 2023Pooled it
- Association between influenza vaccination and SARS-CoV-2 infection and its outcomes: systematic review and meta-analysis.Chinese medical journal · 2022Pooled it
- The Association Between Previous Influenza Vaccination and COVID-19 Infection Risk and Severity: A Systematic Review and Meta-analysis.American journal of preventive medicine · 2022Pooled it
- The safety of co-administration of Bacille Calmette-Guérin (BCG) and influenza vaccines.PloS one · 2022Trial
- Monocyte-derived galectin-1Nature immunology · 2026Article
- Maternal Influenza Vaccine Reduces the Risk of Respiratory Syncytial Virus and Related Respiratory Hospitalizations in Early Infancy: An Epidemiological Study.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2026Article
- The Role of CD4 T Cell Repertoire and Immune Memory Mechanisms in Vaccination and Infection Immunity.Immunological reviews · 2026Review
- SARS-CoV-2-specific immunity after XBB.1.5 vaccination is not significantly altered by subsequent influenza vaccination in dialysis patients.Scientific reports · 2026Observational
- Association between COVID-19 booster vaccination and influenza mortality: a nationwide retrospective cohort study using the SIVEP-Gripe database in Brazil.Immunologic research · 2026Article
- Trained immunity modulators: A new frontier in immunoregulation and disease intervention.Journal of advanced research · 2026Review
- Trained Immunity Induced by Vaccines: A Shifting Paradigm for Infant and Adult Immunity.International journal of molecular sciences · 2026Review
- Monocyte/macrophage-mediated trained immunity in disease prevention and immunotherapy.Bioactive materials · 2026Review
- Respiratory syncytial virus infection induces heterologous protection against SARS-CoV-2 through γδ T cell-mediated trained immunity and the activation of SARS-CoV-2-reactive mucosal T cells.Journal of virology · 2026Article
- Potential Non-Specific Benefits of Seasonal Influenza Vaccination: Evidence, Knowledge Gaps, and Future Directions.Vaccines · 2026Review
- Immune Responses to Influenza Infection in Children.Open forum infectious diseases · 2026Article
- Recent perspectives on macrophage memory: types, mechanisms, and characteristics in pulmonary diseases.Cell communication and signaling : CCS · 2026Review
- Article
- Polysaccharide Adjuvants as Innate Immune Trainers: Bridging Pattern Recognition Receptor (PRR) Activation and Metabolic Reprogramming for Synthetic Vaccine Design.Advanced science (Weinheim, Baden-Wurttemberg, Germany) · 2025Review
- Review
51 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
24 authors at 4 institutions in 3 countries.
Funding
Abstract
Non-specific protective effects of certain vaccines have been reported, and long-term boosting of innate immunity, termed trained immunity, has been proposed as one of the mechanisms mediating these effects. Several epidemiological studies suggested cross-protection between influenza vaccination and COVID-19. In a large academic Dutch hospital, we found that SARS-CoV-2 infection was less common among employees who had received a previous influenza vaccination: relative risk reductions of 37% and 49% were observed following influenza vaccination during the first and second COVID-19 waves, respectively. The quadrivalent inactivated influenza vaccine induced a trained immunity program that boosted innate immune responses against various viral stimuli and fine-tuned the anti-SARS-CoV-2 response, which may result in better protection against COVID-19. Influenza vaccination led to transcriptional reprogramming of monocytes and reduced systemic inflammation. These epidemiological and immunological data argue for potential benefits of influenza vaccination against COVID-19, and future randomized trials are warranted to test this possibility.
Indexed as
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What OpenQuestion holds
Registered trials
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.