Concerning Germany: At this point there are several problems.
First is: We do not have anything near to enough vaccine. That was clear from the beginning. So we have a strict priority list. First group: people in homes for the elderly and people working in clinics. (So one of my grandmothers and my sister got vaccinated early.) Fine. Next are people over 80 in general. They can make appointments. Partly this age group has now been vaccinated. For all of these it's mostly Biontech/Pfizer that's used.
AstraZeneca is only allowed for people under 65. But there are few people which belong into the first priority groups and are under 65. Basically, only people working in elderly care. Some of those didn't want to get vaccinated, since they are often young and female, there were rumors about infetility after vaccination and they are rarely high risk. But in the end, that wasn't a big number of cases. The main problem is the combination of not enough vaccines and bad, or let's say, inflexible organization. (Note, it's done differently in each of our 16 states, and some are a bit faster than others.)
There are several things standing in the way, for instance, obviously, if you don't live in a special home or belong to a clinic (than they come around) the best way to get an appointment is over the internet - but not every over 80 year old here is able to deal with that. (I know my grandparents have never been in the internet. It's unimaginable for some, but very real for others.) So, in some cases children and friends can help out, but in some, well, I guess, they are left behind a bit.
Anyway - when someone doesn't show up to an appointment in most cities there is no clear rule how to deal with that. Sometimes there's an "emergency waiting list", but only for the doses which have already been opened and would otherwise been thrown away. (Sometimes they are given to police and people like that.)
Now in the past weeks teachers of smaller children have been allowed to get vaccinated as well in some of the states. But again, they are usually younger... Mixture of not enough vaccination, vaccination doubts, appointments not being free for them in the beginning (because it was a change of priorities, they are not in the first priority groups originally, but some states wanted to do this to justify school openings when the teachers didn't want that). And so on... It's a lot of bureaucracy and very annoying. But even if everything went smoothly... well, between 70 and 85% of what we got we used, so it's not like there is a huge amount of vaccine that isn't used.
Another aspect: At first, because we were eager to get everyone vaccinated two times like it's supposed to be done, but we weren't sure the supply was coming smoothly (and rightly so), half of the doses were stored. That has changed now. It was also to avoid creating mutants, but that doesn't even make sense in a global world.
The main thought about our program is: there's not enough vaccine, give it first to the most vulnerable. That way the hospitals also will be emptier. But those who feel especially exposed, like teachers, call to be in the first groups.
(It has to be said that most teachers in Germany are officers who cannot be fired and will get their money throughout, but who cannot decline to work, either).
There are some who desperately wait for a vaccination but aren't allowed to get it. And a few who are allowed to, but don't want to. I think if Sputnik gets allowed, a low percentage will be vaccinated with it.
All of this is supposed to change soon, there's talk that in the summer we will have so much vaccine it's going to be hard to get it into people. For now we remain in a constant semi-lockdown. (What will we do with more aggressive mutants that cannot be reached by our vaccines? No idea.)