Effectiveness of influenza vaccination to prevent severe disease: a systematic review and meta-analysis of test-negative design studies

Yegorov S. Patel O.D. Sharma H. Khan T. Gupta R. Yao M. Sritharan A. Silverman N. Pullenayegum E. Miller M.S. Loeb M.
February 2026 Elsevier B.V.

Clinical Microbiology and Infection
2026 #32 Issue 2 219 - 229 pp.

Background Seasonal influenza vaccination may be effective against severe influenza disease. Objectives To assess evidence on the real-world effectiveness of influenza vaccination in preventing severe influenza-related outcomes. Methods Data sources: PubMed, Ovid, and Cochrane CENTRAL from inception to September 24, 2024. Study eligibility criteria Observational test-negative design studies reporting influenza vaccine effectiveness (IVE) against influenza-associated hospitalisation, death, pneumonia, intensive care unit admission, or ventilatory support. Participants Hospitalized adults and children with laboratory-confirmed influenza and inpatient controls who tested negative for influenza infection. Interventions Influenza vaccination. Assessment of risk of bias Newcastle-Ottawa Scale and Grading of Recommendations Assessment, Development, and Evaluation were used to assess study quality and evidence certainty. Methods of data synthesis We extracted study characteristics and ORs or IVE estimates and corresponding 95% CI. Both crude and adjusted estimates were considered and analysed using a random-effects model. We calculated the pooled IVE overall and by season, age group, circulating strains, vaccine type, and match between the vaccine and circulating strains. Results Overall, 7727 publications were identified, 461 reviewed, and 165 included. Pooled IVE was 42% (95% CI: 39–44) against influenza-associated hospitalisation (very low certainty), 36% (95% CI: 24–46) against death (no certainty), 51% (95% CI: 36–63) against pneumonia (low certainty), 52% (95% CI: 38–63) against intensive care unit admission (very low certainty), and 55% (95% CI: 44–64) against ventilatory support (low certainty). IVE varied by age and was generally higher (up to 2-fold) in children compared to adults. Higher IVE was observed against influenza A(H1N1) compared to A(H3N2) and in seasons with good vaccine match. Hospitalisation IVE was slightly higher for quadrivalent (45% (95% CI: 32–56)) compared to trivalent (36% (95% CI: 27–43)) vaccine. Conclusions Seasonal influenza vaccination moderately reduces severe influenza-related outcomes, particularly in children, against A(H1N1), and with a good vaccine-strain match. PROSPERO registration CRD42023476003.

Death , GRADE , Hospitalization , ICU admission , Influenza vaccine effectiveness , Observational studies , Pneumonia , Severe influenza outcomes , Test-negative design , Ventilatory support

Text of the article Перейти на текст статьи

Michael G. DeGroote Institute for Infectious Disease Research, McMaster Immunology Research Centre, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON, Canada
Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, ON, Canada
Michael G. DeGroote Institute for Infectious Disease Research, Health Research Methodology, Evidence, and Impact, Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
Department of Biology, School of Sciences and Humanities, Nazarbayev University, Astana, Kazakhstan

Michael G. DeGroote Institute for Infectious Disease Research
Michael G. DeGroote School of Medicine
Child Health Evaluative Sciences
Michael G. DeGroote Institute for Infectious Disease Research
Department of Biology

10 лет помогаем публиковать статьи Международный издатель

Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026