Something that is definitely happening is we’re getting better at treating the very unwell. Guidelines re stuff like intubation, anticoagulation and use of steroids have changed a lot since early days and we’re getting better outcomes. Mortality in ITU patients in Ireland is at about 20%. Which is a huge reduction from the 50% ITU mortality in the worst effected countries early on in the epidemic.
I’m not aware of any significant change in the risk of being admitted to hospital/ITU for those who get infected though. That would be a seriously positive development. As far as I know, the age adjusted risk of these outcomes hasn’t changed much at all.
I'm not sure of any large scale studies either regarding the supposed less deadly version of covid this time around
Leicester's hospitals have not been beyond capacity despite the massive surge in city centre and some surrounding areas and we had a spike coalesce around one or two weeks and were expecting the worst but didn't happen, primary care has been busy with calls understandably but hot hubs where we see covid patients in "red zones" have been less busy and many winding down, the number of people in Leicester even inner city for those called in for an examination (GPs have to do this with full PPE) has been relatively static.
My experience is that if there was a study that said this time around we've got a less virulent version it wouldn't surprise me.
I've worked around ambulance assessment in ED and triage and have had relatively fewer people to send to resus for stabilising pre-transfer, fewer straight to Glenfield (our hospital with the respiratory ward where most of the NIV is), sent fewer ITU bleeps compared to before
We used to categorise covid patients in terms of clinical pathology as three sometimes overlapping but usually distinct phases
1) early infection/viral response phase that was around 5 days with coryzal symptoms, often unilateral but occasionally bilateral consolidation on chest X-Ray, mildly deranged bloods (mainly lymphopenia, raised ALT and d-dimer)
2a and 2b) where you drifted more into the pulmonary phase where host inflammatory response was predominant - around 4-7 days - where you saw the classical imagining signs of bilateral ground glass change on CT scans and evolving peripheral consolidation (almost always bilateral) along with the usual blood derangement but more notably neutrophilia and a sporting CRP
3) hyperinflammatory phase (small percentage of total covid population base progress to) where pulmonary oedema and ARDS is seen, range 6-10 days on average depending on patient, apart from the obvious pyrexia, dyspnea, increased O2 requirements you also noted worsening consolidation and a couple of other markers are off (like reduced fibrinogen, reduced albumin along with marked lymphopenia)
What happened at the start of this thing was we noted despite what we did for a significant number (although still small as an absolute percentage) many progressed to hyperinflammatory phase or even presented that way. We're seeing a lot more discharges in the early 1 or 2a type phases then we did before (great for patients but also bed capacity). There's also, again anecdote, less multi-organ nastiness from speaking to a friend who's done FY2 ITU placement for 8 months, others things though like difficulty weaning people off the ventilations (plus things like secretions) are still are huge problem.
I think a few clinicians I've spoken to have a feeling that the phase 3 (i.e. the abnormal host immune response to the infection) while still was a low-ish percentage of patients before might be even lower now. And while it still carries significant ventilation needs + mortality risk the rapid progression for patients becoming really unwell really fast is still there but not how sure how much, possibly less compared to what we were noticing before.
I think the resp consultants and ITU consultants for sure have got a hold on this better in terms of a set protocol that is evidence-based to improve outcomes and that's a big factor. But I still wouldn't recommend this as something people take lightly. Considering the very real risk of a few young uns becoming really unwell and those with long tail covid who we are still seeing in significant numbers. Moreover, confirmation bias possibly for a lot of what I'm saying. It could just be that our spike in Leicester now is nothing compared to what we saw before (as data back then was poor)