The US scientists studying the genetic makeup of the Ebola virus in west Africa have identified several mutations that could have implications for developing effective drugs to fight the virus.

“The ‘genomic drift’ or natural evolution of the virus may interrupt the action of potential therapies designed to target the virus’s genetic sequence,” warned senior author Gustavo F. Palacios from the US Army Medical Research Institute of Infectious Diseases (USAMRIID).

According to Palacios, three types of genetic sequence-based treatments are being evaluated during the current outbreak: monoclonal antibody, small-interfering RNA (siRNA), and phosphorodiamidate morpholino oligomer (PMO) drugs.

The team has found more than 600 genetic mutations so far.

Next, they focused on mutations that occurred in the genetic sequences targeted by the experimental therapeutics.

Of these, they found 10 new mutations that might interfere with the mechanisms of the sequence-based drugs currently being tested.

Three of these mutations appeared during the current west African outbreak.

The authors say genetic drift must be considered when developing potential therapeutics, in order to ensure that changes in the Ebola virus over time do not render those treatments ineffective.

Although none of the experimental drugs have been approved by the US Food and Drug Administration, according to the investigators, they are being used to treat small numbers of patients under a World Health Organisation (WHO) emergency protocol.

“Based on these findings, we found the virus has changed and is continuing to change,” said CPT Jeffrey Kugelman, paper’s first author and viral geneticist at USAMRIID.

The findings were detailed in the journal mBio.