The two-year EVIDENT project has achieved the following main results:
- Immune response in survivors: EVIDENT assessed the antibody titers, including neutralizing antibodies, and T cell reactivity in survivors. Neutralising antibody titers remain stable after discharge for long periods of time (at least a year). Thereby glycoprotein-specific antibodies can serve as a surrogate for the neutralising activity. EVIDENT concludes that immune cell responses are likely correlates of protection in survivors. Plasma from survivors should be selected for treatment according to the neutralising antibody titer.
- Management of patients: To improve treatment of patients and support clinical trials, EVIDENT has set-up clinical chemistry measurement in the field. The analysis revealed frequent renal failure, electrolyte disturbance, and evidence for bacterial super infection. Malaria was identified as main co-infection, while chronic virus infections were rare. The analysis of various pathogen and host factors showed that age, virus load, and co-infection with malaria in children 5-14 years of age are independent predictors of poor outcome.
- Ebola virus evolution: Through its sequencing programs in Europe and Guinea, EVIDENT revealed the evolutionary history and molecular clock of the virus during the epidemic with multiple spreading events of the virus across country borders. The Ebola virus evolves during epidemics with a mutational rate comparable to other RNA viruses; emerging mutations may change the phenotype of the virus. Real-time molecular epidemiology based on sequencing in the field greatly enhances tracing of transmission chains and should be an integral part of outbreak response in the future.
- Pathophysiology and immunology of EVD: EVIDENT found that EVD is characterised by serious disturbance of T cell regulation, a pathophysiological feature that might be amenable to therapeutic intervention.
- Virus persistence and shedding: EVIDENT found that Ebola virus persists in various body fluids for long periods of time, remains infectious during persistence, and may be transmitted via breastfeeding or sexual contact.
- Exploitation and Dissemination: Results of EVIDENT have been presented to national authorities, to WHO to be considered in guidelines, to pharmaceutical companies to guide the development of EVD vaccines; and to the wider scientific community. The data have also been published in high-ranking scientific journals, including “Nature” (see EVIDENT publications).
The main socio-economic impact of EVIDENT will result from application of the generated knowledge in the response to future epidemics as well as the development of medical countermeasures in the inter-epidemic time. Both will reduce the impact of future epidemics on the affected population and the economy of the affected countries.