Uganda begins dosing in trial of Oxford's Bundibugyo Ebola vaccine candidate

Africa CDC said at an online press briefing on 8 October that Phase Ib trials of a University of Oxford vaccine candidate against the Bundibugyo strain of Ebola began in Uganda on 6 October, CGTN reported on 9 October, citing Xinhua. The candidate is called ChAdOx1 BDBV.

Wessam Mankoula, an official of Africa CDC (the African Union's public health agency), also said that Moderna's candidate received ethical approval on 7 October for Phase Ib trials in Uganda. Moderna's Phase Ia trials began in Canada in early August.

No vaccine or treatment is specifically approved for Bundibugyo virus. The strain is behind the outbreak in the Democratic Republic of the Congo, where health authorities counted 8,728 confirmed cases and 4,205 deaths as of 6 October, a case fatality rate of 48.2 per cent, according to the CGTN report.

Kenya confirmed its first imported case this month. Xinhua reported on 9 October that the patient was a 40-year-old Kenyan businessman who had lived in the DR Congo and travelled to Nairobi on 3 October via Uganda. He died on 5 October. Kenyan authorities were monitoring 55 contacts, including passengers and crew on the flight from Uganda's capital, Kampala, to Nairobi, World Health Organization Director-General Tedros Adhanom Ghebreyesus said at a media briefing on 7 October.

The Uganda study is run by the MRC/UVRI & LSHTM Uganda Research Unit with the Oxford Vaccine Group and Oxford's Pandemic Sciences Institute. The unit said the first participants were vaccinated in Masaka City on 6 October. Eugene Ruzagira, the unit's head of clinical research and trials, is the principal investigator; Oxford names Professor Simon Drysdale of the Oxford Vaccine Group as the study's chief investigator. The unit's announcement calls it a Phase I study in healthy adult volunteers, and says the Coalition for Epidemic Preparedness Innovations (CEPI) funds both it and the UK trial.

That UK trial, called BD-Ebov, was announced by Oxford on 13 July. It enrols 50 healthy adults aged 18 to 55 in Oxford and assesses the vaccine's safety and immune response. "We are focused on delivering a rigorous phase 1 trial, to the highest standard of care," Professor Katrina Pollock, chief investigator at the Oxford Vaccine Group, said, as quoted by pharmaphorum on 14 July.

The vaccine uses the same ChAdOx1 viral-vector platform as the Oxford/AstraZeneca Covid-19 vaccine. CEPI funds it as part of a US$8.6 million programme for Bundibugyo vaccines, and the Serum Institute of India had made and stockpiled about 620,000 doses in two weeks, Oxford said in July.

The Uganda Virus Research Institute (UVRI) had signalled the plan in May. Its director, Professor Pontiano Kaleebu, said, as quoted by the Daily Monitor on 28 May: "There are two vaccines for Bundibugyo that we are discussing for testing in phase one and phase two trials." One of them is ChAdOx, developed at Oxford.

A different vaccine is already in use in the DR Congo. The country received 70,000 doses of Ervebo, which is approved for the Zaire strain of Ebola but has not been proven effective against Bundibugyo. As of 7 October, 7,775 health and frontline workers had been vaccinated with it under a compassionate-use protocol. A further 848 frontline workers received Ervebo under a separate research protocol called BRAVO, which has been suspended because of supply shortages.

At the same briefing, Tedros said transmission is falling overall but new hotspots are emerging, including near the South Sudan border. He said contact tracing remains below the level needed to contain transmission.

Africa CDC said confirmed cases fell 24 per cent in Ituri province, the epicentre, and 19 per cent in North Kivu over the past three weeks, compared with the three weeks before. Of 64 affected health zones, 47 still have active transmission. Mankoula cautioned that insecurity and community resistance are hampering surveillance, so the declines should be read carefully.