Global Task Force on Cholera Control

Cholera vaccine use: a snap shot

Training course on CDS in emergencies

13.12.2007

Dr Claire-Lise Chaignat Global Task Force on Cholera Control

Global Task Force on Cholera Control

control measures not easy to implement

limited spending on water & sanitation

new approach neededlink environmental management

&Oral Cholera Vaccine use

Kolkata June 2006

Role of cholera vaccines

Global Task Force on Cholera Control

Public Health benefit of cholera vaccines ?

target vulnerable groupsin high risk areas

consider seasonalitywhen usually recommended control measures limited

Immunization

Averted Cases& deaths

Global Task Force on Cholera Control

Currently available & WHO pre-qualified vaccine:

killed WCrB sub-unit OCV*

*Dukoral

• 2 doses in 10 days apart• each dose diluted in

water with buffer• cold chain required• storage capacities needed• high cost• limited availability

Vaccination does not replace, but complement usually recommended control measures

Global Task Force on Cholera Control

1994 Goma, DRC

1997 2000

Uganda

Cholera vaccine use in public health with WHO participation

NO vaccine useFSM Beira Darfur /Aceh, Indonesia

2003/04

WHO recommandations 1999

WHO recommandations 2002WHO recommendations 2005

2004 2005

www.who.int/cholera/publications

Global Task Force on Cholera Control

WHO Recommendations for Cholera Vaccine Use

II. WHO meeting on the use of OCV, December 2002• vaccine use suggested in endemic and epidemic settings

• well designed demonstration projects

I. WHO meeting on use of OCV in emergencies, May 1999• OCV should be considered among tools to prevent cholera

in populations at risk of an outbreak

III. WHO meeting on the use of OCV in complex emergencies, Cairo, December 2005

• relevance of multidisciplinary approach• context of broader public health priorities• 3-step decision making tool developed (to be tested)

Global Task Force on Cholera Control

Decision making tree for OCV use in complex emergencies

Step 1

Step 2

Step 3

Risk of cholera outbreak limited risk OCV use not relevant

Risk exists

Capacity to contain potential outbreakgood coping/response capacities

OCV use not relevant

Feasibility of OCV mass vaccination campaign

Limited capacity

not feasible OCV use not relevant

feasible

Immunization can be considered

Draft 06.03.2006

3-step decision making tool to assess the pertinence of OCV use in complex emergencies

Global Task Force on Cholera Control

Feasibility and Context

• Natural disaster: infrastructure damagedloss of human resourceslimited accesscontinuous threats

• political & economical disruption• complex emergency with armed conflict• endemic areas with seasonal outbreaks• access (security, nat disasters)

Global Task Force on Cholera Control

challenge (1) risk assessment risk perception

• epidemiology endemicity trends over time

• living conditions overcrowding access to water sanitation

• behaviour of community• climatic conditions• context (natural disaster, complex emergency and security issues)

Global Task Force on Cholera Control

challenge (2) target population

• considered at risk• accessible• IDPs / living with host families• high mobility

Influence onnumber vaccines neededvaccine wastage cost

Global Task Force on Cholera Control

Logistics : Volume & Weight of materials required to vaccinate 20 000 people

▪ 40 000 vaccine vials 3.2 m3 (with box)

▪ 40 000 buffer sachets 1.2 m3

▪ 40 000 plastic cups 2.4 m3

▪ 4 000 x 1.5l of water 9 m3

Total weight : 7,100 kg Total volume: 15.8 m3

Global Task Force on Cholera Control

OCVs and unanswered questions

Duration of protection beyond 2 years

role of a booster dose

cost effectiveness

efficacy of OCV in:

children < 2

HIV+

more evidence on herd protection

Global Task Force on Cholera Control

OCV should be part of a comprehensive, programmatic cholera control programme

OCV to be used when they can make a difference