Not really Sinkov
You confuse by referring to a wave of deaths when it’s the wave of infections to which the term second wave relates.
See post 1435 which shows a second wave ending and a third wave starting.

Regarding ICU

A study on 10,287 patients over six months from England, Wales and Northern Ireland admitted to intensive care after falling critically unwell with Covid between February and July.

By the time the study concluded, 3,887 (40 per cent) had died, and 1,725 (18 per cent) were still in ICU.
Some 978 (10 per cent) had been discharged from ICU but were still in hospital, and 3,003 (40 per cent) had been sent to a non-acute setting, where they were assumed to have lived on.
The researchers calculated that the average 28-day mortality rate dropped by 9.5 per cent over the study.
They believe medics grew better at treating Covid-19 patients during that time, boosting survival rates.