this is a highly contagious, fast moving virus .... knowing that, we'd have to assume vaccinated people with covid (not wearing masks, back to normal lives) could be spreading it everywhere
Yes, vaccinated people can still get it and can still spread it. But they generally have a lower viral load.
Normally it takes time for your immune system to get good at fighting the virus. It also takes a certain amount of the virus to make you seriously ill, and you shed a certain amount of that when you cough, talk, sneeze, etc.
Imagine it takes 1000 bugs to make you sick. If you start out with two hundred bugs, and they make baby bugs and now you have 400, and then 800, and 1600. It took just four doublings to get you really sick. Your immune system didn't have much time to respond. And now you're probably really contagious, too.
Imagine that you start with just 2 bugs instead. Now it goes to 4, and then 8, and then 16, 32, 64, 128, 256, 512 and finally 1024. It took much longer - nine doublings- to get up to 1000 bugs.
The healthier your immune system, the less time it takes to figure out how to fight the virus. Maybe that's the time it takes for five doublings. So if you get a smaller load, you'll be fine, but a bigger load will make you sicker.
Masks help to reduce the amount of the virus that you spread.
The vaccine helps three things. One, they help to reduce the time it takes your immune system to learn how to fight those bugs. Two, because your immune system gets good at fighting it earlier, someone who catches it from you will get a smaller load because you never got close to 1000 bugs yourself. So the next guy starts with two bugs instead of 200. Three, the virus needs a host to survive. If it can't spread it dies. When vaccinated people spread it to other vaccinated people, they give smaller and smaller loads to one another until eventually they aren't giving much at all. I give Steve 16 bugs, he gives Amy 8 bugs, Sarah just gets 4 and so on.
When an unvaccinated person gets it, though, they're going to have to rely in their immune system to learn the virus, which means that they get those 8 bugs from a vaccinated person, but it doubles and doubles until they finally beat the virus... but while they were sick they didn't give off 8 bugs, they gave off 64, or 128, or 256. That's a big part of the problem.
Another problem is that unvaccinated people hang out with other like-minded people, and give it to each other. So now you're getting that full sized load when you get sick, and relying on your immune system just like at the peak of this thing. The people who caught it from a vaccinated person got a lower load and probably were asymptomatic spreaders, but the next group starts with a bigger load and spreads it more.
You're right that that's their choice... except when their choice puts others people at risk. Drunk driving is a personal choice, too, and you might be willing to risk your own life to get home tonight, but we have laws against it because there's a chance other people will die. Populations with weak immune systems or who can't get the vaccine are being threatened with large viral loads when there is a simple way to prevent it.
You mentioned the risk of getting a vaccine that we don't fully understand. That's a very real risk. But we also don't fully understand the long term consequences of this illness. The fda has approved the vaccine for emergency use, it has NOT approved the actual virus, because we know the virus is deadly.
You're worried about the long term side effects of taking the vaccine, and I think that's absolutely fine. I was worried about that too. I did not want to be one of the first to take this vaccine. But you also have to consider the long term side effects of the next variant of the virus, which are also unknown. We've already seen worse mutations develop. The more unvaccinated people who continue to spread it, the more likely it is to become more than .1 percent chance of death when an unvaccinated person gets it. If you want to imagine the worst case for the vaccine that's fine, but for your personal choice you should also consider that the vaccine MAY have some unknown long term side effects, but the virus itself DEFINITELY IS becoming more deadly as it mutates.
I don't know if there's any hope for a good faith discussion in the politics forum whether it's specifically with you or anyone else who might read this but this is a good faith argument on my part.
As a computer guy I've always said that you can't skip testing, you can only choose whether to do it in a test environment or in production. The same is true with the vaccine. When I first heard about this i thought they fast forwarded the testing, and I had the same concerns you did. But I've done my research and I understand that that's not what happened. They've vigorously tested this vaccine. It was the development process that was sped up. Understanding that made me decide that it was safe enough for me, and understanding that my choice might literally save my own life or someone else's made the decision obvious.