Pediatric COVID-19 Vaccine Conundrums

Antigen levels in COVID-19 vaccines from both Pfizer and Moderna are different for different age groups with shots for younger persons containing lower levels. Pfizer has different doses for 3 age groups with different colored vial caps for each:

1. 6 months to 4 years (3 µg; maroon cap)
2. 5 to 11 years (10 µg; orange cap)
3. ≥12 years (30 µg; gray cap)

To add to the confusion, children aged 6 months to 4 years need 3 shots to complete the primary series. Sometimes a child will age out of their category between doses. Do you know how to handle this?