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ChAdOx
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ChAdOx

Oxford chimpanzee-adenovirus vaccine platform behind the Oxford-AstraZeneca COVID-19 vaccine and a Bundibugyo Ebola candidate.

Oxford's ChAdOx1 BDBV entered the world's first human trial of a vaccine built against Bundibugyo Ebola on 13 July 2026, a 50-adult safety study backed by about 620,000 doses the Serum Institute of India has already made.

Last refreshed: 4 October 2026 · Appears in 1 active topic

Key Question

How close is the Oxford vaccine platform to having a working Bundibugyo Ebola shot?

Timeline for ChAdOx

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Background

ChAdOx (chimpanzee adenovirus Oxford) is a vaccine platform developed at the University of Oxford's Jenner Institute. It uses a weakened chimpanzee adenovirus that cannot replicate in people to carry genetic instructions for a target antigen into human cells. The platform is best known as the basis of the Oxford-AstraZeneca COVID-19 vaccine, AZD1222, and Oxford has also used it for experimental vaccines against MERS and other emerging diseases.

Its Bundibugyo candidate, ChAdOx1 BDBV, is the first vaccine designed against that Ebola species to reach people. In May 2026 it was still two to three months from trial dosing, ahead of an rVSV-platform candidate six to nine months out. A fourth candidate on the rVSV platform won CEPI seed funding of $1.9m on 9 June 2026.

No vaccine is licensed against Bundibugyo. The frontline vaccine in DR Congo is Ervebo, licensed against Zaire ebolavirus only. MSF's study, launched on 19 September 2026, is giving Ervebo to some 20,000 front-line staff across Ituri and North Kivu, while a randomised ring-vaccination trial is still planned. A purpose-built ChAdOx vaccine would remove the need to rely on cross-protection from another species' vaccine.

Key Issues
Bundibugyo vaccines

ChAdOx leads the Bundibugyo vaccine race

When vaccine funders committed $112m on 1 June 2026 to three Bundibugyo candidates, the ChAdOx version sat inside a CEPI programme worth $8.6m with the Serum Institute of India. The Institute made about 620,000 doses in two weeks and supplied 4,000 to the Oxford Vaccine Group, which opened the BD-Ebov Phase 1 trial on 13 July in 50 healthy adults aged 18 to 55.

The platform's head start has narrowed. Moderna's mRNA-1469 entered human testing in Canada on 3 August, and Egypt's Minapharm won up to $16.5m from CEPI on 27 August for a fifth Bundibugyo-specific candidate. For ChAdOx1 BDBV, the Phase 1 safety and immune-response data now decide whether it moves into larger trials.

Common Questions

ChAdOx leads the Bundibugyo vaccine race

Is the Oxford Ebola vaccine ready to use in the current outbreak?
Not yet. Oxford's ChAdOx1 BDBV vaccine entered its first human trial, a 50-person Phase 1 study in Oxford, in July 2026. The Serum Institute of India has stockpiled about 620,000 doses for possible later use.Source: https://www.seruminstitute.com/worlds-first-phase-i-bundibugyo-ebolavirus-vaccine-trial-launched-by-oxford-vaccine-group.php

Reference

How is the ChAdOx Ebola vaccine different from the COVID-19 vaccine?
Both use the same viral-vector platform, but the antigen delivered differs: the COVID-19 version (AZD1222) carries the SARS-CoV-2 spike protein, while the Ebola candidate carries Bundibugyo ebolavirus antigens to train the immune system against that species.Source: Jenner Institute, University of Oxford
What is the ChAdOx vaccine platform and how does it work?
ChAdOx is a viral-vector platform using a modified chimpanzee adenovirus to deliver antigen instructions into human cells. Developed at Oxford, it was the backbone of the AstraZeneca COVID-19 vaccine and is now being adapted for Ebola and other pathogens.Source: University of Oxford / Jenner Institute
What is the BD-Ebov trial?
The first Phase 1 trial of a vaccine designed against Bundibugyo ebolavirus, launched by the Oxford Vaccine Group on 13 July 2026. It tests ChAdOx1 BDBV in 50 healthy adults aged 18 to 55.Source: https://www.seruminstitute.com/worlds-first-phase-i-bundibugyo-ebolavirus-vaccine-trial-launched-by-oxford-vaccine-group.php
Why was the AstraZeneca vaccine used so widely in developing countries?
The Oxford/AstraZeneca ChAdOx vaccine (AZD1222) was priced for low-income markets, stored at standard refrigerator temperatures rather than ultra-cold, and manufactured at scale in India and elsewhere, making it the most widely distributed COVID-19 vaccine globally.Source: WHO / COVAX
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