There are three things that I find interesting about the reaction in the US and Canada (where I live):
* The hyper/political polarization of it in the US. Not only does the attitude fall right on the Republican/Democrat divide, if you rank states by percentage vaccinated, it's pretty much identical to sorting from Democrat to Republican support (with strong Republican states being at miserable rates, something like 30% at the low end).
* Canada, on the other hand, doesn't seem to have that political divide. Alberta, the Canadian equivalent of the US conservative strongholds, did have some opposition at the start of the year, but seems to have come around.
* Overall, the percentage of Canadians who won't get it is remarkably low, apparently around 14%.
Demand for vaccinations in Canada continues to outstrip supply, whereas in the US many areas are starting to have trouble maintaining their rate.
As for why Republicans don't trust it, I think it boils down to the message that the Republican pundits have been pushing for many years: a distrust of science. Tucker Carlson, in particular, continues to spew lies (implying, for example, that the vaccinations are killing people) on Fox with little to no pushback from the Republicans; see
https://nationalpost.com/opinion/jesse-kline-no-tucker-carlson-vaccines-arent-killing-people-by-the-thousands