Oral cholera vaccines: exploring the farrago of evidence

The development of a cheap and effective oral cholera vaccine (OCV) is a remarkable achievement in the field of cholera prevention. A meta-analysis on the efficacy and effectiveness of OCVs by Qifang Bi and colleagues1Bi Q Ferreras E Pezzoli L et al.Protection against cholera from killed whole-cell oral cholera vaccines: a systematic review and meta-analysis.Lancet Infect Dis. 2017; (published online July 17.)http://dx.doi.org/10.1016/S1473-3099(17)30359-6PubMed Google Scholar updates the estimates of the 2011 Cochrane review.2Sinclair D Abba K Zaman K Qadri F Graves PM Oral vaccines for preventing cholera.Cochrane Database Syst Rev. 2011; 3 (CD008603.)Google Scholar Their analysis includes additional studies published since 2011, yet provides estimates that are almost the same. The debate about the low efficacy of OCVs in children aged…