I'm seeing some discussion of figures in South Africa for hospitalisations and deaths being lower than previous waves of Covid. Several possible explanations, including demographics (younger population); co-morbidities (fewer obese, etc.); vaccine rollout (older people better vaxxed than younger); and more alarmingly, "herd immunity" from prior infection.
This latter is supposedly because SA had a big wave earlier of the Beta variant, which some virologists claim is closer in mutated structure to Omicron. UK did not see much Beta, but had a big Delta wave (which is still going). Beta variant (and likely Omicron) is apparently better at negating effects of AZ vaccine, which as you may know was largely administered in UK to people between ages of 40 and 60. Omicron apparently also shares some characteristics with Gamma variant, which caused big death toll in Brazil but which UK didn't see much of.
TL;DR: - 1. Don't rely on AZ vaccine and get a booster (Pfizer/Moderna) ASAP. 2. Observe social distancing, mask up, etc. Now.