• The case for reactive mass oral cholera vaccinations

      Reyburn, R; Deen, J L; Grais, RF; Bhattacharya, S K; Sur, D; Lopez, A L; Jiddawi, M S; Clemens, J D; von Seidlein, L; International Vaccine Institute (IVI), Seoul, Korea; Epicentre, Paris, France; NICED, Kolkata, India; Ministry of Health and Social Welfare, Zanzibar, Tanzania; Menzies School of Health Research, Casuarina, Australia (2011-01-25)
      The outbreak of cholera in Zimbabwe intensified interest in the control and prevention of cholera. While there is agreement that safe water, sanitation, and personal hygiene are ideal for the long term control of cholera, there is controversy about the role of newer approaches such as oral cholera vaccines (OCVs). In October 2009 the Strategic Advisory Group of Experts advised the World Health Organization to consider reactive vaccination campaigns in response to large cholera outbreaks. To evaluate the potential benefit of this pivotal change in WHO policy, we used existing data from cholera outbreaks to simulate the number of cholera cases preventable by reactive mass vaccination.
    • Feasibility of a mass vaccination campaign using a two-dose oral cholera vaccine in an urban cholera-endemic setting in Mozambique.

      Cavailler, P; Lucas, M; Perroud, V; McChesney, M; Ampuero, S; Guerin, P J; Legros, D; Nierle, T; Mahoudeau, C; Lab, B; et al. (2006-05-29)
      We conducted a study to assess the feasibility and the potential vaccine coverage of a mass vaccination campaign using a two-dose oral cholera vaccine in an urban endemic neighbourhood of Beira, Mozambique. The campaign was conducted from December 2003 to January 2004. Overall 98,152 doses were administered, and vaccine coverage of the target population was 58.6% and 53.6% for the first and second rounds, respectively. The direct cost of the campaign, which excludes the price of the vaccine, amounted to slightly over 90,000 dollars, resulting in the cost per fully vaccinated person of 2.09 dollars, which is relatively high. However, in endemic settings where outbreaks are likely to occur, integrating cholera vaccination into the routine activities of the public health system could reduce such costs.
    • Immunogenicity and Protection from a Single Dose of Internationally available killed oral Cholera Vaccine: a systematic review and meta-analysis

      Lopez, AL; Deen, J; Azman, AS; Luquero, FJ; Kanungo, S; Dutta, S; von Seidlein, L; Sack, DA (Oxford University Press, 2017-11-21)
      In addition to improved water supply and sanitation, the two-dose killed oral cholera vaccine (OCV) is an important tool for the prevention and control of cholera. We aimed to document the immunogenicity and protection (efficacy and effectiveness) conferred by a single OCV dose against cholera. The meta-analysis showed an estimated 73% and 77% of individuals seroconverted to the Ogawa and Inaba serotypes, respectively, after an OCV first dose. The estimates of single-dose vaccine protection from available studies are 87% at 2 months decreasing to 33% at 2 years. Current immunologic and clinical data suggest that protection conferred by a single dose of killed OCV may be sufficient to reduce short-term risk in outbreaks or other high-risk settings, which may be especially useful when vaccine supply is limited. However, until more data suggests otherwise, a second dose should be given as soon as circumstances allow to ensure robust protection.
    • The value of and challenges for cholera vaccines in Africa.

      von Seidlein, L; Jiddawi, M; Grais, RF; Luquero, F J; Lucas, M; Deen, J; Menzies School of Health Research, Casuarina, Australia. (2013-11)
      The 21st century saw a shift in the cholera burden from Asia to Africa. The risk factors for cholera outbreaks in Africa are incompletely understood, and the traditional emphasis on providing safe drinking water and improving sanitation and hygiene has proven remarkably insufficient to contain outbreaks. Current killed whole-cell oral cholera vaccines (OCVs) are safe and guarantee a high level of protection for several years. OCVs have been licensed for >20 years, but their potential for preventing and control cholera outbreaks in Africa has not been realized. Although each item in the long list of technical reasons why cholera vaccination campaigns have been deferred is plausible, we believe that the biggest barrier is that populations affected by cholera outbreaks are underprivileged and lack a strong political voice. The evaluation and use of OCVs as a tool for cholera control will require a new, more compassionate, less risk-averse generation of decision makers.