COVID-19 USA Daily Numbers, page-352

There are a few confounding factors;

• At the time the trial was designed people were going to mechanical ventilation with intubation comparatively quickly on a rapid downhill run, based on the output of the 12 patient study in March it was thought limiting intake to those who had only been intubated for 3 days or less would be OK, rather than using a reliable biomarker, maybe the disease was too new, I don't know.

• As time went by rolling of patients was found to be quite effective, progress to more severe disease was halted for some, those who progressed took longer to do so.

• Various corticosteroids were found to be very useful, again giving more patients time to recover, but extending further the time to intubation.

• Intubation was treated as last resort also in part due to the danger to treating staff who were exposed to aerosols from very sick people as they proceeded with intubation.

As the trial continued those going to intubation are suspected to have progressed to lungs in a progressively worse state, because they have failed to respond to quite a few treatments already. Remestemcel-L proved it was quite good, of great interest in the study, but it does not work magic, not by the time lungs have progressed to being fibrotic, in effect totally scarred, maybe also having other organ failure along the way.

It is the people who have failed to respond to all other treatments who die each day. It is possible the data from the 233 people in the trial may show where the window of best use is and what if anything is compromising effectiveness.

Then there is ever growing spectre of long COVID, those who wind up back in hospital in a matter of weeks or months.