US sends experimental Ebola antibody doses to Congo trials

The United States has sent stockpiled doses of Mapp Biopharmaceutical’s experimental Ebola antibody MBP134 to Congo for compassionate use and clinical trials, putting the therapy into its first direct test in an active outbreak. A Health and Human Services spokesperson said the doses were being made available to help advance a trial in the outbreak region, with the results potentially feeding future regulatory review and possible U.S. approval.

The move comes as the World Health Organization has described the Bundibugyo outbreak as unfolding in a remote, densely populated and insecure area amid a humanitarian crisis. WHO confirmed the outbreak in the Democratic Republic of the Congo and Uganda in May, and the organization’s director-general declared it a Public Health Emergency of International Concern on May 17. WHO convened expert groups on May 28 to assess candidate treatments and vaccines, underscoring how quickly the response has shifted from containment alone toward formal evaluation of experimental countermeasures.

That shift is urgent because Bundibugyo Ebola still has no approved vaccine or specific treatment. The U.S. Centers for Disease Control and Prevention said Bundibugyo virus was first identified in Uganda in 2007, when 149 suspected cases and 37 deaths were reported, and that a 2012 outbreak in Congo caused 56 laboratory-confirmed cases and 17 deaths. The current outbreak has grown far larger: the CDC said that as of June 2 there were 378 confirmed cases and 63 confirmed deaths across Congo and Uganda, while WHO later said that by June 10 Congo had 676 confirmed cases and 136 deaths and Uganda had 19 confirmed cases, including two deaths.

WHO said doses of the Mapp drug and other therapeutics were being shipped and that trial enrollment was being prepared in health facilities. The U.S. supply of MBP134 marked the first time Washington had signaled direct support for clinical trials of the antibody by providing stockpiled doses, a notable step after advocacy groups pressed on June 16 for the drug to be made available not only for Americans but also for clinical trials and emergency use in affected countries.

The outbreak’s early clusters were identified among health care workers in Congo, and both WHO and CDC have pointed to cross-border transmission into Uganda, including secondary spread among health workers. That pattern has made the outbreak not just a test of emergency isolation and contact tracing, but a live trial of whether experimental antibodies, antivirals and later vaccine work can be moved into the field fast enough to generate evidence while cases are still climbing.