- Design
- Stochastic branching-process transmission model, Bayesian calibration
- Population
- Simulated outbreaks calibrated to west Africa 2013–16 and DR Congo 2018–20
- Primary outcome
- Health-worker deaths averted by antiviral PEP
- Effect
- Day-0 readiness: ~80% averted; 1-year scale-up: ~20%; 1–5 day dosing delay: 83% → 50%
A modelling study in Lancet Infectious Diseases (25 August), prompted by the 2026 Bundibugyo virus outbreak in DR Congo, simulated antiviral post-exposure prophylaxis (PEP) for health workers. It used a transmission model calibrated to the 2013–16 west Africa epidemic and the 2018–20 North Kivu outbreak.
Assuming 80% antiviral efficacy, PEP available at full coverage from day one reduced health-worker deaths by about 80% in both scenarios. Scaling up to 80% coverage over six months cut the benefit to 52–60%, and to 50% over a year to about 20%. Delaying doses by one to five days after exposure dropped the benefit from 83% to 50%, even with full coverage. Targeting recognised high-risk exposures, such as PPE breaches, needed 44 doses per death averted against 109 with broad use.
The antivirals themselves are unproven for Bundibugyo virus, and these are model outputs, not trial results. The lesson is operational: stockpiles and same-day access matter more than the drug alone.
- Report every PPE breach or body-fluid exposure immediately, even when it seems minor
- Know who holds PEP and trial protocols in your outbreak response plan
- Prioritise high-risk exposures for prophylaxis over blanket use
- Keep infection-control measures primary; PEP adds to them
Why it matters
It shifts the question from whether an antiviral works to whether a system can deliver it within hours.
Don't overread it
The estimates are model-based and assume an antiviral efficacy that no trial has yet shown for Bundibugyo virus.
The statistics, in plain English
The percentages are medians across many simulated outbreaks, with credible intervals describing model uncertainty, not sampling error from real patients. They depend on the assumed 80% antiviral efficacy, which has not been measured.
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