Original articles

Potential impact of reactive vaccination in controlling cholera outbreaks: An exploratory analysis using a Zimbabwean experience

Sun-Young Kim, Yeongchull Choi, Peter R Mason, Simbarashe Rusakaniko, Sue J Goldie

Abstract


Background. To contain ongoing cholera outbreaks, the World Health Organization has suggested that reactive vaccination should be considered in addition to its previous control measures.

Objectives. To explore the potential impact of a hypothetical reactive oral cholera vaccination using the example of the recent large-scale cholera outbreak in Zimbabwe.

Methods. This was a retrospective cost-effectiveness analysis calculating the health and economic burden of the cholera outbreak in Zimbabwe with and without reactive vaccination. The primary outcome measure was incremental cost per disability-adjusted life year (DALY) averted.

Results. Under the base-case assumptions (assuming 50% coverage among individuals aged ≥2 years), reactive vaccination could have averted 1 320 deaths and 23 650 DALYs. Considering herd immunity, the corresponding values would have been 2 920 deaths and 52 360 DALYs averted. The total vaccination costs would have been ~$74 million and ~$21 million, respectively, with per-dose vaccine price of US$5 and $1. The incremental costs per DALY averted of reactive vaccination were $2 770 and $370, respectively, for vaccine price set at $5 and $1. Assuming herd immunity, the corresponding cost was $980 with vaccine price of $5, and the programme was cost-saving with a vaccine price of $1. Results were most sensitive to case-fatality rate, per-dose vaccine price, and the size of the outbreak.

Conclusions. Reactive vaccination has the potential to be a cost-effective measure to contain cholera outbreaks in countries at high risk. However, the feasibility of implementation should be further evaluated, and caution is warranted in extrapolating the findings to different settings in the absence of other in-depth studies.

Authors' affiliations

Sun-Young Kim, Harvard School of Public Health

Yeongchull Choi, Harvard School of Public Health

Peter R Mason, University of Zimbabwe College of Health Sciences

Simbarashe Rusakaniko, University of Zimbabwe College of Health Sciences

Sue J Goldie, Harvard School of Public Health

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Keywords

cholera; oral cholera vaccines; outbreak

Cite this article

South African Medical Journal 2011;101(9):659-664.

Article History

Date submitted: 2010-12-20
Date published: 2011-09-05

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