PT - JOURNAL ARTICLE AU - Joshua Havumaki AU - Rafael Meza AU - Christina R Phares AU - Kashmira Date AU - Marisa C Eisenberg TI - Comparing alternative cholera vaccination strategies in Maela refugee camp using a transmission model AID - 10.1101/514406 DP - 2019 Jan 01 TA - bioRxiv PG - 514406 4099 - http://biorxiv.org/content/early/2019/08/23/514406.short 4100 - http://biorxiv.org/content/early/2019/08/23/514406.full AB - Background Cholera remains a major public health concern, particularly in refugee camps, which may contend with overcrowding and scarcity of resources. Maela, the largest long-standing refugee camp in Thailand, experienced four cholera outbreaks between 2005 and 2010. In 2013, a cholera vaccine campaign was implemented in the camp. To assist in the evaluation of the campaign and planning for subsequent campaigns, we developed a mathematical model of cholera in Maela.Methods We formulated a Susceptible-Infectious-Water-Recovered-based cholera transmission model and estimated parameters using incidence data from 2010. We next evaluated the reduction in cases conferred by several immunization strategies, varying timing, effectiveness, and resources (i.e., vaccine availability). Finally, we generated post-campaign case forecasts, to determine whether a booster campaign was needed.Results We found that preexposure vaccination can substantially reduce the risk of cholera even when the < 50% of the population is given the full two-dose series. Additionally, the preferred number of doses per person should be considered in the context of one vs. two dose effectiveness and vaccine availability. For reactive vaccination, a trade-off between timing and effectiveness was revealed, indicating that it may be beneficial to give one dose to more people rather than two doses to fewer people, given that a two-dose schedule would incur a delay in administration of the second dose. Forecasting using realistic coverage levels predicted that there was no need for a booster campaign in 2014 (consistent with our predictions, there was not a cholera epidemic in the 2014 season).Conclusions Our analyses suggest that vaccination in conjunction with ongoing water sanitation and hygiene efforts provides an effective strategy for cholera outbreaks in refugee camps. Effective preexposure vaccination depends on timing and effectiveness. If a camp is facing an outbreak, delayed distribution of vaccines can substantially alter the effectiveness of reactive vaccination, suggesting that quick distribution of vaccines may be more important than ensuring every individual receives both vaccine doses.(WaSH)Water, Sanitation and Hygiene (WaSH)(OCV)Oral Cholera Vaccine(WHO)World Health Organization (WHO)(CDC)Centers for Disease Control and Prevention(SIWR)Susceptible-Infectious-Water-Recovered model(PU-AMI)PremiƩre Urgence Aide Medicale Internationale (PU-AMI)(VE)Vaccination Effectiveness (VE)