From an overseas perspective I can tell you that practically nobody in Australia is taking any form of booster. Elderly populations are, particularly those in a care setting but the general population are completely uninterested.

This is a combination of most people having been infected with CV19 at least once and not being particularly badly affected, and most people having had either direct or indirect experience of negative side effects from vaccination, and the now predominantly negative media coverage of the vaccination campaign.

If there is a marked shift towards increased mortality in any given strain, Australia is fucked. Thankfully that does not seem to be the trajectory of the virus at this time.