The Coalition for Epidemic Preparedness Innovations (CEPI) has committed $4.17 million to four studies investigating whether existing or previously licensed Ebola vaccines can trigger immune responses against Bundibugyo ebolavirus.
The studies will analyze thousands of stored blood samples from people who previously received vaccines developed against Zaire ebolavirus, according to a statement issued by CEPI and made available to the News Agency of Nigeria (NAN) on Thursday in Abuja.
The research could provide crucial evidence on whether vaccines such as Ervebo, which was developed to protect against Zaire ebolavirus, can generate antibodies capable of recognizing Bundibugyo virus.
The studies come amid a rapidly escalating Bundibugyo ebolavirus outbreak in the Democratic Republic of Congo (DRC), where no vaccine specifically licensed against the virus is currently available.
CEPI said research teams from the UCLA Fielding School of Public Health in the United States, the Institute of Tropical Medicine in Antwerp, the University of Oxford and the MRC-University of Glasgow Center for Virus Research would lead the studies.
CEPI Chief Executive Officer, Dr Richard Hatchett, said vaccines developed against the related Zaire ebolavirus could provide an important interim tool while researchers continue developing Bundibugyo-specific vaccines.
“There is no licensed vaccine against Bundibugyo virus,” Hatchett said.
He explained that although CEPI was supporting the development of candidate vaccines specifically targeting Bundibugyo virus, those vaccines would not be available during the earliest phase of the current outbreak.
He said the new studies would therefore help determine whether existing vaccines could offer some protection while more targeted vaccines are being developed.
“The researchers will assess vaccine-induced immune responses and specifically examine whether antibodies generated following vaccination against Zaire ebolavirus can cross-react with Bundibugyo virus,” he said.
Hatchett added that the research would also help scientists develop and standardise tests for detecting antibodies against Bundibugyo virus and determine how long vaccine-induced immune responses persist.
He said the UCLA-led study, supported with $2.05 million, would involve more than 1,700 participants and about 1,800 stored serum samples from people who received either Ervebo or the Zabdeno/Mvabea vaccine regimen.
The Institute of Tropical Medicine in Antwerp will receive $1.02 million for a study involving more than 600 participants whose samples were collected during an earlier CEPI-supported vaccine trial.
Hatchett said the first antibody results from the Antwerp study could become available within two to six months.
He said the University of Oxford would use $975,000 to analyse samples from people who received Ervebo and survivors of Zaire ebolavirus disease.
The MRC-University of Glasgow Centre for Virus Research will receive $120,000 to examine samples from vaccinated healthcare workers and close contacts participating in existing research cohorts.
“The studies come as health authorities consider how best to use available vaccines in response to the Bundibugyo outbreak,” Hatchett said.
He added that recent evidence had prompted the WHO Technical Advisory Group on Candidate Vaccine Prioritisation to recommend evaluating Ervebo in a Phase 3 clinical trial alongside Bundibugyo-specific vaccine candidates when they become available.
According to him, DRC authorities and the Africa Centres for Disease Control and Prevention (Africa CDC) have also announced plans to deploy Ervebo to priority groups under a protocol-governed expanded-use approach.
Hatchett said findings from the studies would help address critical knowledge gaps and guide decisions on whether existing vaccines could be used during the current outbreak and future outbreaks caused by related filoviruses.
He added that the research could also contribute to the development and evaluation of vaccines capable of providing broader protection against multiple Ebola virus species.
source:NAN
