A few observations on reopening. I'll focus on the UK and Europe, but other countries with similar population age and mobility profiles have similar questions to answer.
The UK has had a R rate bouncing around 1 since May. The ONS antibody survey gives an idea of why.
In the UK, more than 95% of 18-60 year olds now have covid antibodies. If you use the ONS dataset, in May-July when the UK reopened, 99% of over 60s had antibodies and almost all of them were double vaccinated. Unfortunately those groups now need boosters to get them back up there. Around 70% of under 18s have antibodies.
Around 10m boosters have been done since the ONS collected the blood samples used for those graphs.
In the next month or so the UK will probably be as close to numerical herd immunity as we're ever likely to get, but covid will still be around and still killing people - it won't be leaving, it will become endemic.
It's nice to believe that there's an easy route but even Spain with its high vaccine uptake, some continuing mitigations (masks etc) and low case rates, has over 200 deaths/week at the moment.
Is there a right time? Well, in the UK, they effectively decided to try and let it run through the population before Christmas - leaving February onwards for the flu season. If the vaccine waning effect hadn't hit the vulnerable groups in September, maybe we'd have done better. There's still a good chance though, that with the booster program, hospitalisations and deaths will fall soon. Unfortunately some of the most vulnerable (the 80+ in particular) are not getting their boosters quickly enough - partly because GPs etc are trying to catch up with pent up demand on other health issues.
Some countries, including Germany who managed the initial waves very well, will find full reopening even tougher. Which sends us back to question of whether there is such a thing as a best time to reopen. Every country will have its own version of an "exit wave" and will have multiple waves in the future - hopefully smaller in terms of hospitalisations/deaths.
Any country reintroducing controls now is just buying time. I think they need to know (and preferably state) what they're buying time to do.