As mentioned last week (see prior posts), the independent advisory panel of experts to the FDA recommended the "booster shot" (a third shot of the exact same vaccine formulation) only for those 65 and older.
There had been lots of conflict and controversy over this, in the scientific community, because Pfizer's study only contained 312 people, and using the exact same formulation for a third shot did not appear to fully prove additional benefit - thus, the independent advisory panel recommended to the FDA that only those 65 and older receive the booster (those with low or slow immune systems).
After the independent advisory committee offers its recommendations, the FDA then has the choice to agree, disagree, or agree in part with the advisory panel's recommendations.
Today, the FDA voted and agreed with the independent advisory panel's recommendations - but also added an additional subpopulation.
The FDA decided to authorize a third booster for those 65 and older based on the independent panel's recommendations - PLUS - they added an additional authorization for another subpopulation - those 19 and older who can prove they work in environments at high-risk for COVID exposure (healthcare, teachers, etc).