Ira Longini, Ph.D., a professor in the department of biostatistics at the UF College of Public Health and Health Professions and the College of Medicine, has been part of the driving force behind the design and analysis of Ebola vaccine trials conducted in Guinea. An expert in infectious disease modeling and statistics, Longini spent several months on assignment at WHO’s headquarters in Geneva, Switzerland, as researchers rushed to implement an Ebola vaccine trial. Preliminary results of the trial showed 100 percent effectiveness.
Longini and his colleagues also published some of the first research modeling the 2014-15 Ebola outbreak. In a paper published Sept. 2, 2014 in the journal PLOS Currents: Outbreaks, his team showed a 20 percent chance that an isolated case of Ebola would show up in the U.S. by the end of that month. On Sept. 30 the CDC confirmed the first case of Ebola diagnosed in the U.S. in a man who had traveled from Liberia to Dallas. He passed away Oct. 8.
In the effort to test the safety and efficacy of Ebola vaccines, scientists also had to test how to deploy the vaccinations. Groups with the CDC and the National Institutes of Health’s National Institute of Allergy and Infectious Disease designed two efficacy trials to administer vaccinations in Liberia and Sierra Leone, respectively, that were ultimately unsuccessful. The WHO team, with which Longini is involved, decided to use a ring vaccination design in Guinea.
With ring vaccination, people in contact with those who have contracted a virus, including family members, neighbors and co-workers, receive the vaccination. It is the same approach used in the eradication of small pox.
“The way it’s controlled is by isolating cases and quarantining close contacts of cases, as well as contacts of those contacts,” Longini said. “People who weren’t directly exposed to Ebola were vaccinated, and then monitored for safety and immune response.”