Ebola Vaccine Trial Launches in Uganda

A team of investigators in Uganda has launched a new trial evaluating the investigational Ebola vaccine Ad26.ZEBOV, MVA-BN-Filo.

In the ongoing Ebola outbreak in the Democratic Republic of the Congo (DRC), only Merck’s investigational rVSV-ZEBOV vaccine is authorized to be administered.

The Ad26.ZEBOV, MVA-BN-Filo vaccine regimen is based on AdVac technology from Janssen, and MVA-BN technology from Bavarian Nordic A/S. The regimen is manufactured by Janssen Vaccines & Prevention B.V., part of the Janssen Pharmaceutical companies of Johnson & Johnson.

The trial, ZEBOVAC, which is already underway, is a 2-year study of the immunogenicity and safety of the Janssen vaccine.

The investigational vaccine regimen has been tested in more than 6000 individuals in Europe, the United States, and Africa. It has shown outstanding safety and immunogenicity in humans and is protective against Ebola challenge in nonhuman primates. However, more data is needed to demonstrate efficacy in humans.

The open-label, single-arm study is being conducted at the Epicentre Mbarara at Mbarara University of Science and Technology in Western Uganda and is sponsored by the London School of Hygiene and Tropical Medicine.

Investigators seek to enroll 800 participants into the trial, including health care workers such as physicians, nurses, and pharmacists, along with frontline workers including cleaners, mortuary staff, and ambulance and burial teams. The study will also enroll health workers who provide non-Ebola related care who may encounter ill patients at public or private health centers or clinics.

Study participants will receive a first dose of Ad26.ZEBOV and 56 days later they will receive MVA-BN.

In addition to measuring immunogenicity and assessing safety, the study team also seeks to learn more about Ebola virus disease and transmission, as well as the perceptions and attitudes of participants towards the vaccine.

Health workers are a critical population to protect from Ebola due to their increased exposure—both direct and indirect—to the highly contagious pathogen during outbreaks.

During the early phase of the 2014 outbreak in West Africa, a study in Guinea found that up to 38% of Ebola patients were health care workers with health care-acquired infection transmissions likely in 12 out of 14 cases.

In the ongoing Ebola outbreak in the DRC, there have been 149 cases of Ebola detected among health workers, resulting in 41 deaths, which accounts for 5% of cumulative outbreak cases.

Despite a year-long Ebola outbreak in the neighboring DRC, which continues to grow daily, Ebola case incidence in Uganda has been kept to a minimum.

In June, Uganda registered its first Ebola case in a 5-year-old boy who had recently traveled to the DRC to attend the burial of a family member who died of Ebola. Two other family members were also infected, and all 3 of the individuals died of Ebola.

No additional cases have been recorded since, and in July the World Health Organization along with the Uganda Ministry of Health declared Uganda Ebola-free

“A vaccine, alongside strong community engagement, strengthened diagnosis and real time sequencing, is key to controlling Ebola epidemics. Available vaccines have been used under study conditions as primary prevention or ring vaccination approaches, however currently there is no licensed Ebola vaccine for international use,” Pontiano Kaleebu, MBBS, PhD, director of the Medical Research Council (United Kingdom) and the London School of Hygiene & Tropical Medicine Uganda Research Unit and principle investigator of the trial, said in a statement. “In this trial we hope to avail more information that will help us work towards having a licensed Ebola vaccine.”

For the most recent case counts in the Ebola outbreak in the DRC, check out the Contagion® Outbreak Monitor.