First Human Testing Begins for Bundibugyo Ebola Vaccine

The world’s first clinical trial of a vaccine targeting the Bundibugyo strain of Ebola has begun, marking a turning point in efforts to control the epidemic that has killed more than 700 people in Central Africa.

The early-stage trial will enroll 50 healthy adults to evaluate the vaccine’s safety and immune response. The Serum Institute of India said it has produced and stockpiled about 620,000 doses of the experimental shot in anticipation of further trials and potential emergency use if it proves effective. The company said 4,000 doses have been supplied for the phase 1 study.

The vaccine uses the same chimpanzee adenovirus platform as the Oxford-AstraZeneca Covid-19 vaccine and was developed with funding from the Coalition for Epidemic Preparedness Innovations.

The trial begins 57 days after the World Health Organization declared the Ebola outbreak in the Democratic Republic of Congo and neighboring Uganda an international public health emergency, underscoring how advances in vaccine technology have compressed development times since the pandemic.

Oxford University immunologist Teresa Lambe, who led the scientific development of the vaccine, said in a statement that “the epidemic continues to devastate affected communities and underscores the urgent need for effective vaccines and treatments.”

There is no approved vaccine or specific treatment for Bundibugyo virus. Current licensed Ebola vaccines target the Zaire strain and are not approved against Bundibugyo; This leaves health officials without a vaccine they can administer during the current outbreak.

Even if the Bundibugyo vaccine is successful, it is unlikely to change the course of the current epidemic in the near term. Jean Kaseya, director general of the Africa Centers for Disease Control and Prevention, said early-stage clinical trials “are not an immediate solution for communities facing epidemics today” but are necessary to prepare better tools for future epidemics.

If the current Ebola vaccine provides only limited protection against the Bundibugyo strain, quickly identifying Ebola cases and tracing contacts would reduce deaths more than vaccinating only contacts of patients — a strategy known as ring vaccination — if the current Ebola vaccine provides only limited protection against the Bundibugyo strain, according to peer review and a modeling study released ahead of publication on Monday.

Researchers found that vaccinating larger populations would have the biggest impact if it could be done quickly and at sufficient scale.