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?

1. A child aged 4 years gets his first Pfizer dose (3 µg; maroon cap) 1 week before turning 5. The second dose is recommended 3-8 weeks after dose 1, so the child will be aged 5 for dose 2. To complete the child’s primary series, you tell the mother: