Abstract
Background Health care workers (HCW] are known to be at risk of infection during Ebola virus disease outbreaks, particularly during the early phase when the disease may not have been confirmed or protective measures are not yet implemented. Therefore, vaccination of HCW is currently being considered as a public health intervention, both for personal protection, and to limit outbreak spread. There have not yet been mathematical modelling studies of such interventions, which can integrate both the direct and indirect effects of vaccination to fully quantify their effect.
Methods We studied the dynamics of HCW infections during the 1995 Kikwit outbreak in the Democratic Republic of Congo, and during the 20130-16 West Africa outbreak. We generated a mathematical model that includes different rates of transmission for community and HCW, and the effect of control measures and behavioural change during the outbreak. We generalised the model to explore an higher transmission regime that more closely resembles the patterns seen in the West African outbreak, and assessed the impact of vaccination strategies targeting key groups.
Findings We found that vaccination of health care workers ahead-of-time can greatly diminish the size and duration of outbreaks, but the benefit is dependent on the degree of community transmission. When within-community transmission is sustained, vaccination of the community is required to shorten the outbreak, and decrease the number of cases.
Interpretation Vaccination of HCW ahead-of-time can be a useful strategy for combating Ebola virus disease outbreaks, especially when coupled with other interventions. Vaccination of HCW after an outbreak has started is likely to have little effect on overall transmission, but may help protect HCW.