I get a strong "agile vs waterfall vibe" here, but I guess there's a good point. Russia did just that, i.e. skipped stage 3 clinical trials and progressively vaccinated volunteers. The EU was bashing them for "experimenting on their own citizens", but then had to acknowledge they should have been more aggressive with the trials.
At the same time, despite Russia's early start, they've now administered ~20 million doses, to a population of ~145 million, compared to ~50 million doses administered in the UK, to a population of ~67 million.
We have a natural experiment between countries that waited for standard clinical trials before beginning mass vaccinations, and countries that didn't. It's too early to take the "final score" [accurate, globally accepted final death tolls by country probably won't be available for a year if not years] to see who handled the pandemic best, from beginning to end, but right now it doesn't seem like vaccinating first made for a lasting lead in the vaccination race.
