Even if Ebola has receded from the headlines, a consortium led by a University of Minnesota infectious disease expert is urging world health officials to accelerate the creation of a vaccine against the deadly virus before it re-emerges.
With at least seven vaccines already in development, the consortium calls on global public health leaders to hasten human clinical trials to test their safety — even if data on their effectiveness is incomplete — and build a vaccine distribution system in Africa that is both efficient and trustworthy.
Waiting for another global scare to ramp up vaccine efforts won't work, said Michael Osterholm, director of the U's Center for Infectious Disease Research and Policy and co-author of the report.
"You can't just replace an interstate overpass overnight because somebody wants to do it. It still takes [time]."
Osterholm joined with 25 global leaders on infectious disease following the outbreak that reached epidemic levels in West Africa last year and produced the first-ever cases of Ebola transmission within the U.S. last fall. The group, dubbed "Team B," aims to encourage a pace of vaccine development that would be the fastest in human history.
"It could surely show up anywhere in central Africa," Osterholm said of Ebola, which isn't an airborne virus like influenza but is nonetheless feared for its high fatality rate. "We have to be prepared for … this happening again."
The report, released Tuesday, lists a number of challenges to vaccine development: The science of the virus itself, the constraints of current vaccine manufacturing capacity and safety testing, and the lack of refrigerated storage for mass quantities of vaccines in African areas where Ebola might erupt.
Some vaccines under development have progressed to "Stage 1" trials in which they have been tested on small groups of people, primarily in Europe. The next rounds of testing would require larger use by hundreds or thousands of people in West Africa, where the Ebola virus is prevalent.
But the waning Ebola outbreak in Liberia, Sierra Leone and Guinea will make those trials more challenging, because the main way to know if a vaccine works is to measure if the virus is present in the environment.
More than 23,000 people suffered suspected infections and more than 14,000 died in the current Ebola outbreak, but the number of new cases has slowed in recent weeks.
Cultural issues, too
In response, Team B made the unusual recommendation of pressing forward with human clinical trials to determine the vaccine's safety even if the effectiveness of proposed vaccines remains unclear, or only established through animal testing. Safety testing typically waits until efficacy tests are complete.
The group also encouraged public health leaders to consider the risk level that will be tolerated in the event that a vaccine presents potential side effects — both in the situation of an emerging epidemic and in calmer times when Ebola isn't spreading.
Different vaccines could play different roles, Osterholm said. One might work in a single dose, but provide short-term immunity, and would be perfect to distribute quickly in "hot zones" where the virus emerges. Another might require two doses over time, but work for several years, and would be ideal for health care personnel responding to outbreaks globally.
Significantly, Osterholm said, the report includes contributions from experts in Africa who addressed the challenges of vaccine distribution and acceptance there. The rapid spread of Ebola last year was hastened by communal burial rituals that exposed grieving family members and friends to the virus.
"We ran smack into a culture vs. a science issue," Osterholm said, "so we're laying out a course of how to not have that happen with vaccine."