October 2017

  • Blog post October 4, 2017

    The Incomplete Report

    Jacqueline Deen, MD

    Consultant
    Among the many affected by cholera throughout Yemen, these infected children lie on the ground in a hospital in Sanaa. Photo: KHALED ABDULLAH/REUTERS/Newscom
    Among the many affected by cholera throughout Yemen, these infected children lie on the ground in a hospital in Sanaa. Photo: KHALED ABDULLAH/REUTERS/Newscom

    An article in the World Health Organization (WHO) August Weekly Epidemiological Record (WER) reported that since the creation of the global stockpile for oral cholera vaccine (OCV) in 2013, 55 campaigns have been conducted using nearly 13 million doses [1]. A majority of the OCV doses (73%), were used in emergency settings, while 27% were used in non-emergency settings to control endemic cholera. The report described OCV deployments in terms of the setting, targeted populations, campaign timelines, and coverage. The increasing trend in OCV use in affected countries is an achievement that the WHO can be proud of.

    Oral cholera vaccine use, demand, and production, 1997–2017*, WHO Weekly Epidemiological Record August 2017

    Despite these achievements, we also need to be aware of the emergency situations where OCV was not deployed. Take for example the recent cholera outbreak that began in Yemen in October 2016. The outbreak started to decline a few months after the peak but later resurged in April 2017 following a Saudi airstrike intervention in the Yemeni Civil War [2]. As of August 2017, a cumulative total of 500,000 cholera cases have been reported [3]. One million doses of the vaccine had been allocated from the global stockpile and immunizations had been set to begin in July 2017 but the vaccination campaign was suspended [4]. The article in the WER makes no mention of the Yemeni situation [1].

    Reporting the successful OCV campaigns, as in the WER report [1], is useful for recognizing what is running well, for documenting progress made and for motivation towards continued efforts. But analyzing failure to deploy the vaccine, especially in settings of humanitarian crisis, is arguably even more important. In the Yemeni situation, could the plan to deploy OCV have been made earlier? Could the misconceptions and misinformation that potentially clouded some of the choices have been cleared up? Was there any part of the decision-making process that could have been improved? Answering these questions could increase our understanding of what was tried and what could be improved.

    Additionally, it would be important to know how many applications for vaccine from the stockpile were made overall (as a measure of global demand), how many were granted, how many were denied and the reasons for denying vaccine requests. Guidelines on how to access oral cholera vaccine from the stockpile and a description of the composition and management role of the International Coordinating Group (ICG), are available online [5]. For increased clarity and transparency, we suggest that the details of the decision-making process for each application also be available online. To draw real lessons, both successful and unsuccessful deployments should be publicly discussed.

     

    References:

    [1] Pezzoli L on behalf of the Oral Cholera Vaccine Working Group of the Global Task Force on Cholera Control. WHO Weekly epidemiological record; 2017: 92, 437–52.

    [2] 2016–17 Yemen cholera outbreak https://en.wikipedia.org/wiki/2016%E2%80%9317_Yemen_cholera_outbreak Accessed 23 September 2017

    [3] Cholera count reaches 500 000 in Yemen http://www.who.int/mediacentre/news/releases/2017/cholera-yemen-mark/en/ Accessed 23 September 2017

    [4] Wadman M. Cholera vaccination campaign in Yemen is dropped. Science 2017; 357:

    [5] WHO. Oral cholera vaccine stockpile http://www.who.int/cholera/vaccines/ocv_stockpile_2013/en/ Accessed 23 September 2017

     

  • Blog post October 4, 2017

    Oral Cholera Vaccine Recommendations through the Years

    Anna Lena Lopez, MD

    Research Associate Professor | Inst. of Child Health & Human Development, Univ. of the Philippines Manila-National Inst. of Health
    Three-year-old Salomon looks on as he undergoes treatment for cholera at the general hospital in Minova. Photo: Arjun Claire
    Three-year-old Salomon looks on as he undergoes treatment for cholera at the general hospital in Minova. Photo: Arjun Claire

    On April 25-27, 2017, the World Health Organization (WHO) Strategic Advisory Group of Experts (SAGE) on vaccines and immunization took up oral cholera vaccination during its meeting, with a view of updating the 2010 WHO position paper [1]. WHO regularly releases position papers to guide member states on vaccines and immunization that have global public health importance.

    Provisions for safe water, improved sanitation and hygiene (WASH) as well as appropriate clinical case management have been the mainstays of cholera control. WHO’s position on oral cholera vaccine (OCVs) use has evolved over the years. In the first cholera vaccine position paper in 2001, the WHO solely recommended the pre-emptive use of OCV in high-risk populations [2]. This was further complicated with WHO’s position in 2005, that, “the current internationally-available pre-qualified vaccine (Dukoral) is not recommended once an outbreak of cholera has started” [3]. As cholera outbreaks became prolonged and protracted, such as in Zimbabwe and Angola, and with the availability of a new vaccine (Shanchol) in 2010, the WHO released a recommendation, “to consider the use of oral cholera vaccines in reactive situations” (i.e., when an outbreak has already begun) [4].

    However, since the release of the 2010 position paper, cholera cases persisted, affecting countries that have not seen cholera for many years. In 2013, an OCV stockpile was created that has since released almost 13 million doses of OCV for use in mass campaigns in diverse settings, such as humanitarian emergencies, outbreaks, and areas with endemic cholera [5].

    Experiences from these campaigns have shown that a two-dose OCV schedule is safe, feasible, acceptable and effective in all settings. A single dose of the vaccine was also shown to be efficacious for six months in a study in a cholera-endemic setting [6]. Additionally, studies among pregnant women have shown the vaccine to be safe [7].

    With an accumulating body of evidence on OCV use, and increasing OCV supply by licensure of yet another vaccine in December 2015 (Euvichol), a revised set of recommendations is expected from the WHO SAGE. It is anticipated that the new position paper will provide concrete guidance on the use of OCV not only in endemic areas but during humanitarian crises and in times of outbreaks as well [1]. This will clarify the role of OCV in cholera control and hopefully stop the misconceptions and misunderstandings on OCV use and implementation, particularly in countries where OCVs are most needed.

    References:

    [1] WHO. Meeting of the Strategic Advisory Group of Experts on immunization, April 2017 - conclusions and recommendations. Releve epidemiologique hebdomadaire / Section d'hygiene du Secretariat de la Societe des Nations = Weekly epidemiological record / Health Section of the Secretariat of the League of Nations. 2017;92:301-20

    [2] WHO. Cholera vaccines. Releve epidemiologique hebdomadaire / Section d'hygiene du Secretariat de la Societe des Nations = Weekly epidemiological record / Health Section of the Secretariat of the League of Nations. 2001;76:117-24.

    [3] Chaignat CL, Monti V. Use of oral cholera vaccine in complex emergencies: what next? Summary report of an expert meeting and recommendations of WHO. Journal of health, population, and nutrition. 2007;25:244-61.

    [4] WHO. Cholera vaccines: WHO position paper. Releve epidemiologique hebdomadaire / Section d'hygiene du Secretariat de la Societe des Nations = Weekly epidemiological record / Health Section of the Secretariat of the League of Nations. 2010;85:117-28.

    [5] WHO. Deployments from the oral cholera vaccine stockpile, 2013-2017. Releve epidemiologique hebdomadaire / Section d'hygiene du Secretariat de la Societe des Nations = Weekly epidemiological record / Health Section of the Secretariat of the League of Nations. 2017;92:437-42.

    [6] Azman, AS et al. Effectiveness of one dose of oral cholera vaccine in response to an outbreak: a case-cohort study. The Lancet: Global Health. 2016; 10.1016/S2214-109X(16)30211-X

    [7] Mohammad Ali et al. Safety of a killed oral cholera vaccine (Shanchol) in pregnant women in Malawi: an observational cohort study. The Lancet: Infectious Disease. 2017; 10.1016/S1473-3099(16)30523-0