Thread by @ewanbirney

One consistent thing in this pandemic is for a given virus biology (parameters of infection, immune escape, disease severity) the growth or reduction fits models / understanding well

(A short diversion here between forecast/now cast models - accurately predicting the next handful of days - and scenario models - helping decision makers plan given uncertain parameters and choices for intervention-

Forecast models absolutely should be benchmarked to outturn. Scenario models for the discovered parameters and interventions benchmarked by shape and size but less so timing)

For omicron scientists rapidly worked out it escaped immunity and had high transmission; that 2 dose vaccines offer little protection to symptomatic infection (likely some protection vs severe) but 3 doses (boosted) works well bs mild and presumed severe

After the first week the scenario models all pointed to rapid growth in Europe - this has come to pass in London and Copenhagen; probably omicron is growing fast in other places in Europe, masked in aggregate due delta

For commentators, journalists and politicians therefore - the infection growth we are seeing was virtually inevitable. And there will be considerable hospitalisations ahead of us.

Can healthcare systems cope? I don’t know (I hope so) but a reminder that exponential growth is very hard to match with fixed or linearly increasing at best healthcare capacity

My heart goes out to London NHS colleagues who have another exhausting Christmas ahead. Stay safe all.