Let Republicans Rapture
You've got a vaccine, you've made it available to everyone in the USA, they've had plenty of opportunity to get vaccinated, that's as much as you can do.
Let Republicans go meet their makers if they want to. Their Republican leaders are all vax'd up, if the leaders catch it, they're off to hospital for the latest anti-body treatments and anti-virals. None of that horse wormer treatment for them. What they tell their supporters to do, and what they do themselves are polar opposites.
The Republican leaders are liars not idiots. Their nutjobs supporters, will never get vaccinated and you can do nothing to fix that.
You cannot stall the opening forever.