Clinical Scorecard: Evaluation of Access to Licensed Vaccines for High-Risk Infectious Diseases: A Comprehensive Review and Interpretive Analysis of Ebola Virus Disease

At a Glance

Key Highlights

• EVD has a high case fatality ratio averaging 67%, reducible to ~25% with intensive supportive care and pre-symptom vaccination.
• Two WHO-prequalified vaccines exist: Ervebo (single-dose) and Zabdeno/Mvabea (two-dose), with Ervebo used in ring vaccination strategies.
• Challenges remain in vaccine stockpile management, deployment, and implementation, with significant doses expiring unused despite ongoing outbreak risks.

Guideline-Based Recommendations

Diagnosis

• Diagnosis is complicated by nonspecific initial symptoms; gastrointestinal manifestations and severe dehydration often follow.
• Survivor follow-up is critical due to viral persistence and potential transmission from immune-privileged sites.

Management

• Intensive supportive care reduces mortality significantly.
• Vaccination before symptom onset is recommended to reduce disease burden and interrupt transmission chains.

Monitoring & Follow-up

• Monitor vaccine stockpile usage and expiration to optimize deployment.
• Surveillance of outbreaks and viral persistence in survivors to guide vaccination strategies.

Risks

• High risk of transmission to healthcare providers and close contacts through bodily fluids.
• Transmission risk from burial practices and viral persistence in recovered individuals.

Patient & Prescribing Data

Individuals exposed to or at risk of EVD, including contacts of confirmed cases and survivors with documented viral persistence.

Ervebo is recommended for ring vaccination during outbreaks and for contacts of survivors with viral persistence; either Ervebo or Zabdeno/Mvabea may be used preventively in at-risk populations.

Clinical Best Practices

• Implement ring vaccination strategies targeting primary and secondary contacts during outbreaks.
• Ensure follow-up and vaccination of survivors with documented viral persistence and their close contacts.
• Maintain and monitor vaccine stockpiles to prevent wastage and ensure rapid deployment during outbreaks.
• Provide intensive supportive care alongside vaccination to reduce mortality.
• Adopt WHO SAGE recommendations for vaccine use during outbreak and preventive settings.

References

• WHO Prequalification of Vaccines
• International Coordinating Group on Vaccine Provision
• Gavi, the Vaccine Alliance Preventive EVD Vaccination Program