SIX THINGS ABOUT THE NEW EBOLA VIRUS

1 MUTATIONS

The Ebola virus mutated to more effectively infiltrate human cells during the West African outbreak that killed more than 11,300 people between 2013 and 2016, according to two teams of virologists in studies published Thursday in the journal Cell.

2 RECEPTOR CHANGE

The scientists identified a mutation that changed the part of the virus that fits into receptors on the exterior of the host cell. Once inside the cell, the virus could hijack its reproductive machinery and begin making copies of itself.

3 DOMINANT STRAIN

Within months of the first appearance of this mutated strain, it was able to dominate the epidemic. At least 90 per cent of those who were infected contracted the mutant version of the virus.

4 GLYCOPROTEIN ‘KEY’

The Ebola epidemic that began in Guinea in late 2013 was the biggest in history — 100 times more people were infected than in any previous outbreak. When researchers reconstructed the evolutionary tree of the virus, they noticed that one mutation — a single nucleotide change on a gene responsible for building the glycoprotein “key” — seemed particularly persistent.

5 TOO RISKY TO TEST

One of the research teams attached the mutant glycoprotein to a different virus (Ebola virus is so dangerous it’s rarely experimented on in labs) and tested its ability to infiltrate host cells. They found the mutant was much more efficient at entering the cells of humans and other primates than the standard version.

6 ‘NEW HOST’

“Once it’s in humans, that’s the new host,” said Jonathan Ball, a professor at the University of Nottingham. “It’s really got to acquire adaptations and get the most fit for human-to-human transmission.” And that’s what it appears the Ebola virus did.