Influenza: marketing vaccine by marketing disease

This Feature (BMJ 2013;346:f3037, doi:10.1136/bmj.f3037) listed an incorrect lower confidence interval for the US Centers for Disease Control and Prevention vaccine effectiveness study that it cites (reference10). The last sentence of Box 2 should have stated that this study’s vaccine effectiveness was 27%; 95% confidence interval, −31% (not “31%”) to 59%.