Dec 2, 2023Liked by Oliver Johnson

One thing that may give pause here though. The competitive advantage of any given variant is a composite of two factors: immune evasion and changes in R0. Immune evasion expands the susceptible pool, increased R0 runs through the susceptible pool faster.

I think it’s possible that BA.2.86 and derivatives have sacrificed some intrinsic infectiousness for greater immune escape. That would explain the relatively low competitive advantage for a variant that’s really quite a large saltation in sequence terms.

That means that while this next wave might build slower than (say) BA.5, it might go on for longer because it will have a larger susceptible pool to chew through before it dies down.

At the moment we only really have enough data to predict the steepness of the rise, not really the level of the peak.

Expand full comment