Comparative effectiveness of influenza vaccination dosing strategies for cardiovascular protection: A systematic review and network meta-analysis of randomized controlled trials.
Joshua J Hon, Tadao Aikawa, Tor Biering-Sørensen et al.
✦ AI-curated · Sources linked
In 30 seconds
This systematic review and network meta-analysis of randomized trials compared high-dose, double standard-dose, standard-dose, and no influenza vaccination in adults with established cardiovascular disease. Ten trials enrolled 131,908 participants. Compared with no vaccination, standard-dose vaccination was associated with a lower risk of the composite cardiovascular endpoint (RR, 0.74; 95% CI, 0.61-0.90), as well as lower risks of all-cause death, cardiovascular death, and myocardial infarction. Network comparisons found no statistically significant head-to-head differences between dose strategies; standard dose ranked highest for mortality and composite outcomes.
Key findings
- Standard-dose vaccination versus no vaccination was associated with lower composite cardiovascular risk (RR, 0.74; 95% CI, 0.61-0.90).
- Standard-dose vaccination was associated with lower all-cause death (RR, 0.75; 95% CI, 0.64-0.89), cardiovascular death (RR, 0.63; 95% CI, 0.42-0.93), and myocardial infarction (RR, 0.76; 95% CI, 0.62-0.94).
- No significant reductions were observed for stroke (RR, 1.06; 95% CI, 0.72-1.54) or heart failure hospitalization (RR, 0.96; 95% CI, 0.60-1.54).
- No head-to-head dose comparison reached statistical significance; higher-dose formulations showed no established incremental cardiovascular benefit over standard dose.
Why it matters
These findings support the cardiovascular relevance of influenza vaccination in people with established cardiovascular disease, while distinguishing evidence for vaccination versus none from evidence comparing doses. The absence of significant head-to-head differences means that apparent rankings among formulations should not be interpreted as proof of superiority. The reported mortality benefit was concentrated in trials enrolling patients during acute cardiovascular admission.
What to keep in mind
The network meta-analysis found no statistically significant head-to-head dose differences, and the directional high-dose advantage for heart failure hospitalization came from a single trial and requires confirmation.