Cholera

Joint WHO/UNICEF statement for cholera vaccine use in tsunami-affected areas

Background

  • Traditional parenteral whole-cell (WC) cholera vaccine has never been recommended by the World Health Organization (WHO) because of its low protective efficacy and its high reactogenicity.
  • Currently available oral cholera vaccines (OCV) are safe and offer good protection (over 70%) for an acceptable period of time (at least one year).
  • The use of OCV is considered as an additional public health tool to usually recommended cholera control measures such as provision of safe water and adequate sanitation.
  • OCV use is recommended for populations to limit the risk of:
    • occurrence of cholera outbreaks in displaced populations in endemic areas,
    • spread and incidence of cholera during an outbreak.

Currently commercially available OCV (Annex 1)

  • Live attenuated single-dose cholera vaccine CVD 103-HgR, Orochol-E®, contains a live attenuated strain derived from reference strain 569B (classical, O1, Inaba) presented in a single dose.
    • Protective efficacy was reached 8 days after administration of the vaccine in a volunteer's challenge study.
    • Therefore, use of the single dose OCV may be possible once an outbreak has started.
  • Killed WC B subunit cholera vaccine (WC/rBS), Dukoral®, derived from mixtures of WC killed strains. They are given in two doses, 10-14 days apart.
    • Protective efficacy is reached 10 days after the second dose.
    • The two-dose OCV is currently not indicated for use once an outbreak has started.

Neither of the two vaccines protects against Vibrio cholerae O139.


1References: WHO/CDS/CSR/EDC/99.4; WHO/CDS/CPE/ZFK/2004.5; WER 2001; 76:117-24.

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