Objectives: A number of cost-effectiveness analysis of influenza vaccination have been conducted to estimate value of influenza vaccines in elderly and health workers (HWs). This study aims to summarize cost-effectiveness evidence by pooling the incremental net monetary benefit (INMB) of influenza vaccination.

Methods: A systematic review was performed in electronic databases from their inceptions to November 2020. Cost-effectiveness studies reporting quality-adjusted life year (QALY), or life year (LY) of influenza vaccination were included. Stratified meta-analyses by population, perspective, country income-level, and herd-effect were performed to pool INMB across studies.

Results: A total of 17 studies were included. Fifteen studies were conducted in elderly, while two studies were conducted in HWs. For elderly, four studies reported LY and 11 studies reported QALY. For HWs, one study reported LY and another study reported QALY. According to pre-specified analyses, studies for elderly in high-income countries without herd effect could be pooled. For societal perspective, pooled INMB was $217·38 (206·23, 228·53), while that for healthcare provider/payer perspective was $0·20 (-11,908·67, 11,909·07). The findings were robust across a series of sensitivity analyses. Studies in HWs indicated that influenza vaccination was cost-effective compared to no vaccination or current practice.

Conclusions: Influenza vaccination might be cost-effective for HWs and elderly under a societal perspective, while there remains limited evidence for healthcare provider/payer perspective. Further evidence from such perspective is warranted.