Ebola outbreak in West Africa has claimed over 8,500 lives, with over
21,000 cases confirmed. With no cure, experimental drugs and vaccines are being
developed to tackle the disease. These therapies target specific sequences in
the viral genome. However, the virus is rapidly mutating through a process called
According to Dr Gustavo Palacios, director of USAMRIID and
lead author on the current study, this could affect how potent the new drugs
are: 'We wanted to highlight an area where genomic drift, the natural process
of evolution on this RNA virus genome, could affect the development of
Dr Palacios' team worked with research groups from Harvard University and the Massachusetts Institute of Technology and compared
the current strain of Ebola with two previous strains that caused outbreaks in
1976 and 1995 in the Democratic Republic of Congo (formerly Zaire). In each
comparison, they found more than 600 mutations to the Ebola genetic code.
Of these 600 mutations, the team found ten that could
interfere with genetic sequences targeted by the experimental drugs. Seven of
these mutations occurred between 1976 and 1995. The remaining three mutations
occurred after December 2013, during the current outbreak.
'The virus has not only changed since these therapies were
designed, but it's continuing to change,' lead author Dr Jeffrey Kugelman, a
viral geneticist at USAMRIID and captain with the US Army, said. 'Ebola researchers
need to assess drug efficacy in a timely manner to make sure that valuable
resources are not spent developing therapies that no longer work.'
The findings were published in American Society for
Microbiology journal mBio.