Meanwhile in Australia - we're not waiting on scientific & safety data - third shot already purchased and planned for early in 2022.

WASHINGTON (AP) — Dealing the White House a stinging setback, a government advisory panel overwhelmingly rejected a plan Friday to give Pfizer COVID-19 booster shots across the board, and instead endorsed the extra vaccine dose only for those who are 65 or older or run a high risk of severe disease.
The twin votes represented a heavy blow to the Biden administration’s sweeping effort, announced a month ago, to shore up nearly all Americans’ protection amid the spread of the highly contagious delta variant.
The ruling came from an influential committee of outside experts who advise the Food and Drug Administration.
WATCH: FDA holds debate on efficacy of COVID vaccine boosters
In a surprising turn, the panel rejected, by a vote of 16-2, boosters for almost everyone.