From the article itself: “Once researchers in the BU lab developed the combined COVID-19 strain, they injected large amounts of it into mice, to determine how deadly each version of the virus is and again, what part of the virus causes this severity level.
With the original strain of COVID-19, 100% of the mice died. With Omicron, none of the mice died. And with the combined strain, about 80% of the mice died.”
So they in fact did develop and combine two strains. It’s a bit of some semantics, but the concerning point for me is that they are playing around with it at all. Because “research”. And a little misleading as the original was 100% lethal. Still. . . Playing god with this stuff is probably what got us in this mess to begin with.