This was immediately obvious from the data. Every country that introduced mass vaccinations saw a massive jump in case numbers right after the vaccines were introduced. Countries that didn't introduce the vaccines until later didn't see that initial jump in cases. Their numbers continued to drop.
This was immediately obvious from the data. Every country that introduced mass vaccinations saw a massive jump in case numbers right after the vaccines were introduced. Countries that didn't introduce the vaccines until later didn't see that initial jump in cases. Their numbers continued to drop.