A pair of Ebola vaccines that University of Minnesota researchers have been testing for two months is safe for use, marking an important step toward a new immunization. The National Institute of Allergy and Infectious Disease determined that the vaccines appeared to be safe after they were tested on more than 600 people in Liberia. Researchers from the UniversityâÄôs School of Public Health are working with NIAID to finish the second part of the immunizationâÄôs clinical testing by the end of the month to ensure it wonâÄôt harm anyone who is vaccinated. The next step is to begin testing to see if the injection is durable enough to protect someone from Ebola. The virus has quickly declined in Liberia, where officials are testing vaccines containing live and dead Ebola viruses. Because of the decline, researchers hope to conduct the next phase of their research in Sierra Leone and Guinea, where Ebola continues to impact the population, said Jim Neaton, the projectâÄôs leader and a biostatistics professor. âÄúThis was a very important recommendation,âÄù he said, adding that the next phase will consist of less data collection and more investigation into possible serious adverse reactions to the vaccine. Moving into Sierra Leone and Guinea for investigation requires researchers to establish relationships with those countriesâÄô governments, which could take time, Neaton said. Researchers will continue testing in Liberia until the end of April, he said. They plan to reach about 1,500 participants by the time they move on to other countries. Marisa Eisenberg, assistant professor of epidemiology and Ebola expert at the University of Michigan, said that while transmission has decreased significantly in Liberia and slightly in Sierra Leone, Ebola is persistent in Guinea. âÄúThe West Africa outbreak is still continuing,âÄù she said. âÄúThereâÄôs still a lot to do in terms of getting us to the end of that outbreak.âÄù The difficulty that public health officials are having in eradicating the virus has led them to question whether the outbreakâÄôs pattern is different compared to previous Ebola outbreaks. Even with a working vaccine for humans, Eisenberg said, an inadequate understanding of the other animals the virus lives in, like fruit bats, could still cause the disease to spill into the human population. Still, Eisenberg said itâÄôs possible to eradicate Ebola altogether. âÄúThe big thing is that thereâÄôs a lot more research that needs to be done in terms of understanding why this epidemic was so different from the previous patterns,âÄù she said. âÄúItâÄôs going to be really important to interface that as the vaccine is developed.âÄù The next phase of the vaccineâÄôs testing, in which researchers will sample blood to gauge the vaccineâÄôs sustainability in humans, is expected to last at least one year, according to a NIAID press release. While researchers are aware of the vaccinationâÄôs short-term results, they donâÄôt know what to expect from the next phase. âÄúYou take things one step at a time,âÄù Neaton said. âÄúOnce you have efficacious vaccines, you can do lots of other planning.âÄù The National Institutes of Health plans to work with University researchers to study the long-term consequences of the virus beginning in May and continuing for several years, Neaton said.