Experimental vaccine may have saved scientists from Ebola

Writing in the British Medical Journal, Annette Tuffs says that a scientist from the Bernard Nocht Institute for Tropical Medicine in Hamburg who was quarantined for a week because of a possible infection with the Ebola fever virus has left the isolation ward of Hamburg University Hospital. She has been transferred to a normal ward, because she had no clinical signs of infection, and neither the virus nor any antibodies against the virus were found in her blood.

This positive development may be due to the use of an experimental vaccine given to the scientist that has never previously been used in humans. The vaccine virus was found in her blood shortly after vaccination but vanished within two days, indicating that the patient's immune system had eliminated it.

On 12 March the Hamburg scientist, who had been working in a high security laboratory on a project to produce antibodies against the Ebola virus, had pricked herself through three layers of safety gloves with a needle containing the virus. The particular virus type is lethal in 90% of infections.

The benign outcome may have been aided by the swift reaction of the international Ebola research community, members of which were contacted by colleagues of the Hamburg scientist. Within 48 hours the scientist was given an experimental attenuated live vaccine against the virus, which had been shown to be effective in monkeys but which had not yet been tested in humans.

The vaccine was developed by Heinz Feldmann and former colleagues at the National Microbiology Laboratory of the Public Health Agency of Canada, in Winnipeg, Manitoba, along with Boston University virologist Thomas Geisbert, who tested it in macaque monkeys at the US Army Medical Research Institute of Infectious Diseases, Frederick, Maryland. One of their experiments on rhesus monkeys was published in 2007 in PLOS Pathogens (2007;3(1):e2, doi:10.1371/journal.ppat.0030002).