tetano
Editor, Senior Moderator
Clin Microbiol Infect
. 2026 Jun 23:S1198-743X(26)00330-7.
doi: 10.1016/j.cmi.2026.06.018. Online ahead of print.
Effectiveness of high-dose versus standard-dose influenza vaccines against severe respiratory and secondary cardiovascular outcomes in adults aged ≥80 years
Laura Díaz-Estévez[SUP] 1 [/SUP], Mario Rivera-Izquierdo[SUP] 2 [/SUP], Nicolás Francisco Fernández-Martínez[SUP] 3 [/SUP], Daniel Ocaña-Rodríguez[SUP] 4 [/SUP], David Moreno-Pérez[SUP] 5 [/SUP], Nicola Lorusso[SUP] 6 [/SUP]
Affiliations
Objectives: Vaccination is a key measure to prevent severe influenza in adults aged ≥80 years, who experience the highest burden of respiratory and cardiovascular complications. Because immunosenescence reduces the effectiveness of standard-dose vaccines (SD-IIV), enhanced formulations such as high-dose vaccines (HD-IIV) are recommended in the elderly. Real-world data on their effectiveness in adults aged ≥80 years remain limited. The aim of this study was to quantify the relative vaccine effectiveness (rVE) of HD-IIV versus SD-IIV in preventing severe influenza disease in adults aged ≥80 years, assessed through respiratory and cardiovascular outcomes.
Methods: Retrospective, population-based cohort study conducted in Andalusia, Spain, during the 2024-2025 influenza season, including 279,649 vaccinated adults aged ≥80 years. Data on sociodemographic characteristics, influenza vaccines, chronic diseases and clinical outcomes were taken from the Andalusian health population database. We used a directed acyclic graph to illustrate the assumed relationships between variables. The rVE of HD-IIV versus SD-IIV was estimated using augmented inverse probability weighting models.
Results: Compared with SD-IIV, HD-IIV was associated with a lower risk of hospitalisation for influenza (rVE=34.0%; 95%CI=15.8% to 52.2%). HD-IIV also showed improved effectiveness against laboratory-confirmed influenza (rVE=42.1%; 95%CI=22.9% to 61.3%), hospitalisation for acute myocardial infarction (rVE=26.4%; 95%CI=5.6% to 47.2%), for stroke (rVE=32.9%; 95%CI=17.4% to 48.4%), for pulmonary embolism (rVE=26.7%; 95%CI=0.7% to 52.6%) and for overall cardiovascular outcomes (rVE=6.6%; 95%CI=0.9% to 12.2%). No association was observed for hospitalisation due to pneumonia, influenza/pneumonia, heart failure, respiratory outcomes, or in-hospital mortality.
Conclusions: Among adults aged ≥80 years, HD-IIV seemed more effective than SD-IIV in preventing hospitalisation for influenza and secondary cardiovascular outcomes, supporting its use in this at-risk population.
. 2026 Jun 23:S1198-743X(26)00330-7.
doi: 10.1016/j.cmi.2026.06.018. Online ahead of print.
Effectiveness of high-dose versus standard-dose influenza vaccines against severe respiratory and secondary cardiovascular outcomes in adults aged ≥80 years
Laura Díaz-Estévez[SUP] 1 [/SUP], Mario Rivera-Izquierdo[SUP] 2 [/SUP], Nicolás Francisco Fernández-Martínez[SUP] 3 [/SUP], Daniel Ocaña-Rodríguez[SUP] 4 [/SUP], David Moreno-Pérez[SUP] 5 [/SUP], Nicola Lorusso[SUP] 6 [/SUP]
Affiliations
- PMID: 42336235
- DOI: 10.1016/j.cmi.2026.06.018
Objectives: Vaccination is a key measure to prevent severe influenza in adults aged ≥80 years, who experience the highest burden of respiratory and cardiovascular complications. Because immunosenescence reduces the effectiveness of standard-dose vaccines (SD-IIV), enhanced formulations such as high-dose vaccines (HD-IIV) are recommended in the elderly. Real-world data on their effectiveness in adults aged ≥80 years remain limited. The aim of this study was to quantify the relative vaccine effectiveness (rVE) of HD-IIV versus SD-IIV in preventing severe influenza disease in adults aged ≥80 years, assessed through respiratory and cardiovascular outcomes.
Methods: Retrospective, population-based cohort study conducted in Andalusia, Spain, during the 2024-2025 influenza season, including 279,649 vaccinated adults aged ≥80 years. Data on sociodemographic characteristics, influenza vaccines, chronic diseases and clinical outcomes were taken from the Andalusian health population database. We used a directed acyclic graph to illustrate the assumed relationships between variables. The rVE of HD-IIV versus SD-IIV was estimated using augmented inverse probability weighting models.
Results: Compared with SD-IIV, HD-IIV was associated with a lower risk of hospitalisation for influenza (rVE=34.0%; 95%CI=15.8% to 52.2%). HD-IIV also showed improved effectiveness against laboratory-confirmed influenza (rVE=42.1%; 95%CI=22.9% to 61.3%), hospitalisation for acute myocardial infarction (rVE=26.4%; 95%CI=5.6% to 47.2%), for stroke (rVE=32.9%; 95%CI=17.4% to 48.4%), for pulmonary embolism (rVE=26.7%; 95%CI=0.7% to 52.6%) and for overall cardiovascular outcomes (rVE=6.6%; 95%CI=0.9% to 12.2%). No association was observed for hospitalisation due to pneumonia, influenza/pneumonia, heart failure, respiratory outcomes, or in-hospital mortality.
Conclusions: Among adults aged ≥80 years, HD-IIV seemed more effective than SD-IIV in preventing hospitalisation for influenza and secondary cardiovascular outcomes, supporting its use in this at-risk population.