I don't see why vaccines for this would be required honestly. Most (nearly all) people have had the vaccine, exposure, or some combination thereof. Thus, everyone is fairly well-protected. Also, today's variants are not as severe as what was going around in 2020. It's not even a close comparison. Also, the vaccine does not necessarily even prevent illness at all. In fact, I caught coronavirus and got sick two weeks after getting the booster back in January. So, I don't think it's all that effective. At least, it's quite ineffective for some people IMO. This doesn't seem entirely unusual.
After all, drugs and medications can work very differently from one person to another. Thus, the vaccine could work for some people and not others. There are a lot of variables at play, such as the health of one's immune system and past infections/exposure to coronavirus. Plus, there could be other factors at play that doctors aren't even aware of yet. The human body is exceedingly complex, and modern medicine still does not understand everything. We're not even close. Normally, it takes 4-5 years to develop a vaccine.
However, this one was created in around a year. Now, it's been a little over a year since it was released. So, it's probably better understood than it was early on. Though, there are still unknowns. In addition to the fact that it does not work for everyone, there is a possibility of serious side effects for some people, as is the case for every drug/medication. I'm not saying that the risk outweighs the benefit necessarily, but I think that we might not know the answer to that question for everyone. We also might not understand the effects of repeated booster doses.
There could be "long-term effects" associated with getting vaccinated over and over again. There's no way to say whether there is or isn't yet with any degree of certainty. Rather, we just don't know. So, I really don't agree with the idea of mandating that people get it. Ordering people to take a drug/medication of any kind just seems wrong to me honestly. It's a violation of people's body autonomy. People who do want to take the vaccine aren't really endangered by people who choose not to get it, especially not at this point.
Honestly, the disease itself is somewhat unremarkable. It's a virus that causes illness in a majority of people who get it, but the overall risk of death from it is quite low. In general, Covid-19 is a lot like the flu. So, why is it that everyone is treating it so differently with vaccine requirements (and even forced testing in some industries) being so commonplace? It's almost as if those in power are using this to prepare everyone for some sort of new societal structure where the authorities have greater control over our lives. Who knows exactly where that would lead? But it probably wouldn't be good.