First Ebola vaccine trial in DR Congo begins in Bunia

The World Health Organization announced on Friday that the first participants in a clinical trial in Bunia, Democratic Republic of Congo, received Ervebo, an approved vaccine for the Zaire strain of Ebola. The trial, called Tumaini (also rendered Tomayni or TUMAiNi), will evaluate whether Ervebo or other candidate vaccines can protect against the Bundibugyo strain behind the country's current outbreak. Africanews reported that the launch event took place in Bunia on Saturday, with the National Institute for Biomedical Research leading the trial and WHO providing technical, scientific and logistical support.

The outbreak, declared in mid-May, is the worst and fastest-growing Ebola epidemic in DRC history, with more than 9,700 cases and over 4,600 deaths. WHO has declared the outbreak a public health emergency of international concern, its second-highest alert level. Four countries have reported cases in this outbreak, giving it the broadest geographic spread of any Ebola outbreak on the continent to date. Kenya has reported nine cases, Nigeria confirmed its first case this week, and Uganda ended its Ebola outbreak in August after 20 cases.

Ervebo is approved for the more common Zaire strain, but no vaccines or treatments are approved against Bundibugyo virus. The trial will test whether Ervebo provides cross-protection against Bundibugyo and whether candidate vaccines designed for that strain work. WHO director-general Tedros Adhanom Ghebreyesus said, "This trial will help us understand whether any of the vaccine candidates designed for Bundibugyo virus work". He also said, "Science gives us hope".

The trial uses a ring vaccination approach, immunising contacts considered at high risk of infection, and enrolls pregnant women and children who are 12 years or older. It is designed to evaluate the safety, efficacy and immunogenicity of several vaccines. Two Bundibugyo-specific candidates, a ChAdOx1 adenoviral vector vaccine from the University of Oxford and an mRNA vaccine from Moderna, will soon join the trial, according to CEPI. Both candidates are now in earlier, smaller clinical studies and have received funding from CEPI.

Ituri Province's governor, Major General Kasongo Gaby, said the launch was significant and reflected "our shared determination not to passively accept health threats".

The trial is in its earliest stage, so no efficacy or safety results are available, and it is too early to know whether Ervebo or any candidate will offer protection against Bundibugyo. Ervebo's existing approval is for the Zaire strain, not Bundibugyo, and the study is designed to answer whether cross-protection exists.