Second doses are boosting people from ~85% to ~95% protected while first timers go from 0% protected to ~85% protected

See A Majority of Doses are Now Second Doses by Alex Tabarrok.

"As of Feb. 18 (last day of full data) we gave out 817,708 second doses and just 702,426 first doses. In other words, a majority of doses are now second doses. As Daniel Bier writes this means that we are boosting some people from ~85% to ~95% protected when we could be vaccinating more first timers and getting them from 0% protected to ~85% protected.

If we followed the British rule and delayed the booster to 12 weeks, we could immediately more than *double* the number of people going from 0% protected to to ~85% protected. More first-doses would be great for the newly protected and more people at ~85% protection would also reduce transmission so there would be fewer new infections and less threat to the non-vaccinated.

The opportunity cost of not delaying the booster is measured in lives lost."