Why? Here's my proposed explanation: (THREAD)
The lockdown dramatically changed this balance between young and old.
(A) The average reproduction ratio R taken over the whole population distribution, under the current UK lockdown, looks to be much lower than has been estimated from hospital admissions. That gives our decision-makers some powerful new options.
(B) During lockdown the disease has likely remained embedded in the older portion of the population, which is now a potential infection source for the wider population, where the disease has been rapidly clearing. Going forward, demographically targeted measures will be key.
(C) With this insight we can see that a strong lockdown, combined with strong test-and-trace measures and quarantining of international arrivals, has the capability to not only control the epidemic, but eliminate the disease entirely, as has been done in New Zealand.
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