January 2015

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Ebola Vaccine Prompts Immune Response

An experimental vaccine to prevent Ebola virus disease was well-tolerated and produced immune systemProtects your body from invading viruses and other threats. responses in all 20 healthy adults who received it. Based on these results, researchers are planning further studies to assess the safety and effectiveness of the vaccine.

The Ebola virus spreads through direct contact with body fluids from an infected person. The 2014 Ebola outbreak in West Africa is the largest Ebola outbreak in history. As of early December, more than 17,000 cases and 6,000 deaths have been reported. There are no approved drugs, but early care can improve survival.

Beginning in 2003, NIH developed and supported human testing of 3 experimental Ebola vaccines. The vaccine assessed in the new study was developed by scientists at NIH and at the pharmaceutical company GlaxoSmithKline based on knowledge gained from the earlier research.

Twenty volunteers between the ages of 18 and 50 participated in the clinical trial, which took place at the NIH Clinical Center in Bethesda, Maryland. Ten received lower dose and 10 received higher dose vaccines.

All 20 volunteers produced anti-Ebola antibodies within 4 weeks of receiving the vaccine. Antibody levels were higher in those who received the higher dose vaccine.

The vaccine also prompted creation of protective immune cells called CD8 T cells. Four weeks after vaccination, CD8 T cells were detected in 2 volunteers who had received the lower dose and 7 who had received the higher dose vaccine.

No serious side effects were seen in any of the volunteers. This and other Ebola vaccine candidates continue to be evaluated by international research teams.