(This commentary was not written by CRD, but by the authors of the DH Register.) 1) Health effects are not explicitly addressed although incapacitation days might be a useful proxy measure. 2) 85% effectiveness is optimistically assumed in prophylactic use: this may not be achieved when local antimicrobial resistance has developed. 3) The main influence for the savings is the value of incapacitation days, determined as loss of investment - a conservative evaluation of production loss. 4) The quality of evidence is poor but the findings appear robust in the sensitivity analysis.