posted a report of it on a website scientists use to quickly share developments, but the paper has not been formally reviewed or published in a journal.HOW DO THESE NEW STRAINS OCCUR?Viruses often acquire small changes of a letter or two in their genetic alphabet just through normal evolution.
A slightly modified strain can become the most common one in a country or region just because that’s the strain that first took hold there or because “super spreader” events helped it become entrenched.
A bigger worry is when a virus mutates by changing the proteins on its surface to help it escape from drugs or the immune system. “Emerging evidence” suggests that may be starting to happen with the new coronavirus, Trevor Bedford, a biologist and.