None of the available covid vaccines are sterilizing vaccines. They've always been (in effect) saving throws against the worst effects of becoming infected. If you've been vaccinated, you're less likely to die.
That's all we can say with confidence.
Omicron is less likely to kill you than Delta, we think, on present data. What happens to an older population than the one from which the South African data is drawn from is not well understood.
That would be good news if Omicron didn't spread so fast. Infectiousness is worse than severity because severity is linear and infectiousness is exponential. Even if the median case is milder, many more cases give you a substantial pile of corpses. Many more cases gets you more damaged people with curtailed agency, and there's no evidence Omicron is less damaging than other variants. Truly many more cases, the million-infections surges that are entirely plausible in a lot of places, crash the health care system and then people die because they can't be treated for other things.
Against wild type, if there had been a fast, mandatory rollout of the mRNA vaccines, these vaccines might, stress might, have been sufficiently effective to stop spread. This was never a possibility against Delta and (in the same conditions, presently, in Ontario) Omicron has a doubling time one tenth that of Delta.
We have no immediate prospect of a vaccine that can stop spread. (That is, a sterilizing vaccine.) It's not impossible; there's several lines of research that might get there by 2030. But for planning purposes, we don't have one and won't get one.
Covid always hurts you; that's what comes out of the UK wild-type initial wave. Maybe a small amount, maybe massively, but any covid-19 infection comes with damage. There's a little bit of anecdata that repeat infections are worse. The damage is poorly understood and currently untreatable. Unconstrained spread of the covid-19 clade of viruses -- which is a widespread policy position! -- means you catch it every year until something kills you. It might not be covid, but something will and it'll be rather sooner than would otherwise have been the case. That's the Uncommon Cold scenario, where the outcome is like that of a major plague in antiquity and the population shrinks by a quarter with dire economic consequences.
What can you do?
Get vaccinated; get boosted. Induced immunity isn't durable -- just like the common cold! -- and it doesn't last more than six months. It's less if you're older. It won't keep you from getting infected and it won't keep you from getting hurt and it won't keep you from transmitting the disease, but it might keep you from dying. (It might reduce your odds of being hurt badly; given that no one has figured out the mechanism for "long covid" yet, this one is open.)
Remember -- and this is a conscious, considered, ongoing effort kind of remembering -- that it's a virus. This is the domain of necessity, like needing potable water and not eating arsenic. How you feel about it, your moral stance, your loneliness, none of them have any primary meaning. Duty requires that necessity be respected. (There being no just way to value your convenience above the lives of others.)
Part of what duty requires is recognizing that the status quo ante pestis shall not return; it is one with Thebes the Golden. Insist on this understanding in yourself and from politicians.
Wear a mask. Wear the best mask you can get; N95 -- real ones -- is the minimum ante against Omicron. Better is to be prefered. Wear means you put it on, properly fitted, before you leave your house and it stays on, continuously properly fitted, until you return. None of this "oh I am outside, outside is safe" nonsense. (Outside is not as risky. Equating "not as risky" with "safe" is what is known as a mistake.)
Children are not protected by childhood innocence; children get infected, transmit, and are damaged about like adults. Sometimes they die. If the kid can't wear a mask, they stay in the bubble.
Act like you know you're infected. Act like you know everyone else is infected, too.
Stop trying to negotiate with a virus. It doesn't care if you've been virtuous. It exists to convert the amino acid guts of your cells into more viruses. It has no awareness of you as an organism; to a virus, you're landscape. If it helps to think of it as killer alien nano machinery, do that. (Only "alien" is wrong.)
The two long-term policy options are extirpation and the Uncommon Cold. Demand recognition of this choice from yourself and effective extirpation measures from politicians. ("effective" does not mean "provided it continues to permit doing a mammonism"; it means "the disease is extirpated at the lowest cost in human agency, and we don't weight the agency, everybody's counts the same".)
Don't move around. The virus can't spread if people do not come into contact. Go home and stay home. (If we could arrange for absolutely everyone to be able to do this for three weeks, that'd do it. It's way cheaper than the Uncommon Cold.)
Remember that the bill comes due. The common good and the public peace and the civil order aren't free; there's a cost. Usually that cost is remember to behave peaceably. Sometimes that cost is higher, and this is one of those times.
Edited: s/about/above/, remove second instance of an adjectival phrase.