Despite relatively rapid travel restrictions, Omicron will soon become the dominant variant of COVID in the UK. It has been able to achieve this by reinfecting people that have previously had COVID or vaccinations - hence it is best described as a "sneaky" variant. There is positive anecdotal evidence that Omicron is "far milder". Still, MUCH higher case numbers might translate into unacceptably high hospital admissions. The critical question is: can the NHS cope with this wave of COVID without a national lockdown? Recent modelling from LSHTM suggests that hospitalisations could peak in late January 2022 at levels between half and double the January 2021 peak (see chart below - dotted lines show January 2021 peak).
This modelling leaves a lot of room for uncertainty. Still, as some excellent analysis from James shows (here), it currently looks most likely that the Omicron wave would result in a similar level of hospitalisations as the Alpha wave last January - albeit at a potentially quicker rate.* This better case scenario is due to vaccinations and previous infections protecting against severe disease and hospitalisation. Boosters will also have a significant effect. No analysis has yet to consider the additional impact of molnupiravir; the antiviral approved for use in the UK in November. Early evidence for molnupiravir suggests that it reduces hospitalisations between 30% - 50%. Combined with the above analysis on possible hospitalisations, the Omricon wave could be significantly lower than the Alpha wave of January 2021 - possibly half as many admissions with a shorter length of stay, so even fewer beds (my semi-scientific guesstimate).
Unfortunately, the NHS was stretched pre-COVID and has been pushed to its extremes during COVID and the recovery. Staff are exhausted and some traumatised. As my GP friend put it: "honestly, everyone is shattered...it's unsafe in lots of places". This triangulates with anecdotal evidence that sickness rates are twice as high compared to this time last year - the chart below shows NHS sickness data over the previous three years up to August 2021.
Add to all of this:
a likely spike in NHS staff sickness due to (re)infection with COVID
a general increase in NHS pressure (which would have been rising even without the pandemic)
a growing backlog of 'non urgent' activity that is rapidly becoming 'urgent'; and
a (bizarrely timed) reorganisation
and the NHS may well face an even more challenging test in January 2022 than 2021!