@rockyroller To save lives, the important metric is the percentage of over 60s that have been fully vaccinated (but the US measure is, I guess, easier to collect/report). The IFR starts ramping up from then. Increasingly this measure may need to be amended to: 'a dose within the last 7 months' given the expectation of waning protection seems to have been realised.
For the under 40 age goups the IFR rate is so low that however that half of the population get antibodies, mercifully very few will succumb - still better to achieve that by vaccination though.
Must confess some forriner suspicion (that's me that's the forriner) that the Iberian Peninsula has achieved such a high %, and wonder whether there are denominator issues in play (ie they don't actually know an accurate number in each age cohort).