Technical Note The Use of Oral Cholera Vaccines for International Workers and Travelers to and from Cholera-Affected Countries November 2016

Background

Three Oral Cholera Vaccines (OCVs) are currently pre-qualified by WHO: Dukoral – a vaccine used mainly by travelers that includes killed whole cells and a component of the cholera toxin – and Shanchol and Euvichol, which contain only killed whole cells. All three vaccines have a two-dose regimen with an interval between doses of two weeks or more (three doses for Dukoral in children aged 2–5 years). All also have a good safety profile. Shanchol and Euvichol are have the same formulation and comparable safety and immunogenicity profiles and are reformulated versions of Dukoral.1,2 Unlike Dukoral, Shanchol and Euvichol do not require a buffer to administer. Shanchol has demonstrated longer term protection – a rather stable 65 – 67% from Year 2 to Year 5,3,4,5 as compared to Dukoral.6 Concerning short-term protection – of most relevance to travelers – Dukoral has been shown to provide 79-86% for three to six months in a series of studies,4,7,8,9 while the single published study of the short-term effectiveness of Shanchol found a similar rate (87%) over six months.10 Dukoral has been shown to also confer significant short-term protection against enterotoxigenic E. coli (ETEC).