I wouldn't be so sure that there's nothing to worry about with the Delta variant - it's now 95% of the UK's new infections, and their rate right now is the highest it's been since early Feb, before many people got vaccinated - if the %'s were applied to the US, we'd be having 120k new infections/day instead of the 10k/day we have right now - we've been lucky that the Delta variant hasn't yet become the dominant strain here, but it could easily take over in those mostly unvaccinated southern red states and become the dominant strain, especially since it's more transmissible than the original variant or UK variant. We are lucky the Beta variant from SA never showed up here in big numbers - vaccine efficacy against that one is relatively poor.