Even the original vaccine/s will protect you somewhat from even the newer variants on a sliding scale - least from infection and most from hospitalisation and death.
Boosters don’t protect as much additionally as your original 2-3 vaccinations, but still add some additional protection, for at least weeks and maybe months.
The bivalent boosters will protect a little better against Omicron variants than original boosters initially, and possibly even better over the following 6-9 months, which is yet to be confirmed, but likely based on ‘vaccine science’
The nuance for boosters is that for the very young, especially young males, the risk of Myocarditis and Pericarditis reactions to additional boosters increases. Mostly these reactions are temporary, but they can do some permanent damage or become chronic. The risks are very small, but large enough to contend with risk from COVID itself, especially in young, fit males. A few months ago, boosters were not recommended for anyone under 30, but that has been revised to under 18 currently. ATAGI is far more cautious than the CDC in this regard, where 2 vaccines plus a bivalent booster are recommended for everyone over 6 months old.
Also, regardless of age, boosters are not recommended within 3 months of a previous vaccine/booster or a confirmed infection. Which makes it tricky if you’ve had a suspected infection in the last 3 months. If that were the case, then I’d be inclined to err on the side of safety (get the booster) as your risk profile increases, i.e. age or underlying conditions, but probably best discussed with your regular doctor.
@Hoffy posted an article from the AMA above reminding us about how post infection risks from COVID continue to increase as we have subsequent infections. While I believe it’s very hard to avoid COVID altogether, you can strike a balance with your risk of subsequent infections with boosters, and generally being a little more conservative socially, especially during peaks of new waves. I know people on both extremes, some who are still terrified of COVID, and others who don’t take any precautions at all. As usual, somewhere in the middle is probably more sensible. To me, vaccinations and ventilation/air filtration are the most obvious and least intrusive precautions you can take that still allow you to be more sociable. Masks still make a lot of sense to protect others if you have a respiratory illness and have to go out.
This unseasonably cold weather in Victoria, right as this wave is peaking, and just before Christmas/New Year is perfect timing to make Victoria’s COVID figures look worse than more Northern states. For some reason, Victorians can never catch a break with this thing!
https://www.health.gov.au/news/atagi-recommendations-on-use-of-the-pfizer-bivalent-originalomicron-ba1-covid-19-vaccine