The covid distributions were well known a couple months in.
The vulnerable actually needed more protection. Isolation, cleanse everything delivered from the outside.
The healthy cohorts should have continued as normal.
Of course, that's assuming the next pandemic isn't in 100 years when we forget everything we learned this time around.
Paradoxically, most of the big governments had plans in place for years, even decades, but they were not targeting the correct virus, and they had a hard time adapting to something unknown.
Next time, it will be different, and we should only be prepared to that.
How can we ethically get such a theory? Cancer. Tailor make a vaccine targetting the particular cancer cell a given patient has. If you give this as a hail-mary to those with a bad prognosis it becomes a win-win.