Much is being said about Covid variants spreading sequentially faster. A couple of days ago I posted a comment on this in response to @jburnmurdoch
https://twitter.com/jburnmurdoch/status/1463956686075580421?s=20
As we approach endemicity new variants are expected to outcompete others faster. Reason being recovered subpopulation (less immune to novel variants as long as there is some immune escape) grows as we approach endemicity increasing the benefit of novelty.
Illustration from model:
Illustration from model:
When replacement is by immune escape the second variant (B) outcompetes previous faster than first variant (A) had done: 
When replacement is by a mixture of immune escape and increased transmissibility this appears to happens to a lesser extent:
Finally when replacement is by increased transmissibility alone this does not seem to happen:
Just sharing this for now to illustrate what I meant.
More explanatory details are being written up.
One think I should perhaps add now is that B relates to A in the exact same way that A relates to Wildtype (otherwise the whole exercise would be meaningless).
One think I should perhaps add now is that B relates to A in the exact same way that A relates to Wildtype (otherwise the whole exercise would be meaningless).
* thing
x-tick labels in bottom panel are time since relative incidence crosses a specified threshold (2% but could be something else). x-tick labels in bottom panel are not the same as above panels.
• • •
Missing some Tweet in this thread? You can try to
force a refresh
