The University of Oxford has opened the first human trial of a vaccine against Bundibugyo ebolavirus, the species behind the outbreak that has now passed 3,200 cases in the Democratic Republic of the Congo, and the full protocol summary is now public in the ISRCTN registry. Registered on 13 July under the identifier ISRCTN72157798, it is the document that sets out what the trial will actually do, in detail that the announcements around it did not carry.

The design is a Phase Ia randomised, double-blinded, placebo-controlled study of the ChAdOx1 Ebola BDBV vaccine in fifty healthy adults aged 18 to 55, run at a single site, the Centre for Clinical Vaccinology and Tropical Medicine at the Churchill Hospital in Oxford. It runs in two stages. An open-label first cohort of ten participants all receive a single dose, with no placebo and no blinding — the standard cautious opening for a vaccine no human has received before. Only then does a second cohort of forty enrol, randomised three to one, so thirty receive the vaccine and ten receive saline.

The follow-up burden differs sharply between the two groups, which is a detail worth reading. The first cohort attends screening, two vaccination visits and nine in-person follow-ups, and returns at six months for a booster in a second phase of the study. The second cohort attends screening, a single vaccination and six follow-ups. Recruitment opened on 20 July and is scheduled to close on 30 September; the study as a whole runs until 31 December 2027.

The timetable is the part that stands out. The World Health Organization dates the start of the outbreak to 14 May. Recruitment for a first-in-human trial of a vaccine against the responsible virus opened on 20 July — sixty-seven days later. The Coalition for Epidemic Preparedness Innovations, which is funding the work at $8.6m, says the partnership was agreed within two weeks of the outbreak being declared, and that the Serum Institute of India manufactured and stockpiled roughly 620,000 doses in a fortnight, supplying 4,000 investigational doses for this trial.

That sequence inverts the usual one. The doses were made before the trial that will establish whether they are safe to give, which is a deliberate bet: manufacturing at risk during an outbreak, on the assumption that if the safety data comes back clean there will be no time left to start production. It is the same logic that shortened the Covid-19 vaccine timeline, applied to a far smaller outbreak and a far narrower stockpile.

The registry also records the constraints. The trial is sponsored by the University of Oxford, approved through the London-Brent research ethics committee under reference 26/LO/0481, and led scientifically by Professor Teresa Lambe. Its exclusion criteria bar anyone who has previously received a ChAdOx1- or ChAdOx2-vectored vaccine — which, after the Oxford-AstraZeneca Covid-19 programme, excludes a substantial share of the British adult population — and anyone who has travelled within the previous 42 days to a country with a WHO-declared filovirus outbreak, naming DR Congo and Uganda.

One line in the file is a straightforward negative: under its data-sharing policy, the registry records that individual participant data is “not expected to be made available”. For a publicly funded, philanthropically backed first-in-human trial of a vaccine intended for an ongoing outbreak, that is a choice rather than an oversight, and it is recorded nowhere else that a reader can easily reach.