- Design
- Stochastic household-community network transmission model
- Population
- Simulated outbreak calibrated to 2026 DR Congo Bundibugyo data
- Primary outcome
- Mortality and incidence reduction over 90 days; doses per death averted
- Effect
- Enhanced detection and tracing −81.6% (73.1–87.7); plus ring vaccination −83.6%
This stochastic network model, calibrated to the 2026 Bundibugyo virus outbreak in DR Congo, compared outbreak-control strategies over 90 days. Because rVSV-ZEBOV protection against Bundibugyo is unproven, it assumed a hypothetical vaccine with 45% effectiveness. It was published in The Lancet Infectious Diseases in September.
Raising case detection from 30% to 70% and tracing from 30% to 80%, without vaccination, reduced expected mortality by 81.6% (95% uncertainty interval 73.1 to 87.7). Ring vaccination of contacts of contacts added 10.5% on top of that. Community vaccination at 80% coverage gave the largest reduction (86.6%) but needed 54 to 111 doses per death averted.
The lesson for outbreak planning is that detection, isolation and tracing come first. A partially effective vaccine adds value mainly if delivered quickly and broadly.
- Invest first in case detection, isolation and contact tracing.
- Treat ring vaccination as an addition, not a substitute, while vaccine efficacy against Bundibugyo is unknown.
- Screen returning travellers from affected areas with a clear viral haemorrhagic fever pathway.
- Know your local isolation and referral route before a suspected case arrives.
Why it matters
It shows public-health basics outperform an unproven vaccine in an Ebola-family outbreak.
Don't overread it
The results are simulated; the vaccine's effectiveness against Bundibugyo is assumed, not known.
The statistics, in plain English
These figures are model outputs, not observed outcomes. Uncertainty intervals reflect the model's assumptions, including the chosen 45% vaccine effectiveness, which has not been measured.
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