Immunization, Vaccines and Biologicals

WHO issues updated cholera vaccines position paper

In an updated position paper on cholera vaccines published in the August edition of the Weekly Epidemiological Record, WHO incorporates recent developments in the field of cholera and provides revised guidance on the target populations for immunization.

Cholera prevention and control should be a priority in areas at risk for cholera or where endemic cholera is present. Given the current availability of oral cholera vaccine and data on their safety, efficacy, field effectiveness, feasibility, impact and acceptability in cholera affected populations, these vaccines should be used in areas with endemic cholera, in humanitarian crises with high risk of cholera, and during cholera outbreaks. The vaccines should always be used in conjunction with other cholera prevention and control strategies.

Vaccination should not disrupt the provision of other high priority health interventions to control or prevent cholera outbreaks. Appropriate case management, WaSH interventions, surveillance and community mobilization remain cornerstones of cholera control.

Vaccination complements the other prevention and control measures and should be implemented in relevant settings as part of comprehensive cholera control strategies or while the other activities are being developed.

In all settings, a series of criteria should be considered to guide the decision to vaccinate:

  • The risk of cholera among the targeted populations and the risk of geographic spread;
  • The programmatic capacity to cover as many persons as possible who are eligible to receive the vaccine and living in the targeted area;
  • Implementation of previous oral cholera vaccine campaigns. Cholera vaccination should not be carried out if a campaign has been conducted in the previous 3 years in the same population, unless justified by continuous transmission resulting from inadequate vaccine coverage during the previous campaign and/or substantial population movements.

Cholera is a rapidly dehydrating diarrhoeal disease and is spread mainly by faecal contamination of water and food and is closely linked to poor sanitation and lack of clean drinking water.

Approximately 1.3 billion people are at risk of cholera in endemic countries. An estimated 2.86 million cholera cases occur annually in endemic countries. Among these cases, there are an estimated 95 000 deaths. About half of the cholera cases and deaths are estimated to occur in children under 5 years of age, but any age group may be affected. Two types of oral cholera vaccines are currently recommended for use by WHO.