According to both the FDA News Release and the letter, it's under emergency use authorization for all ages, not only for 12-year olds and for booster shots.
"I am authorizing the emergency use of Pfizer-BioNTech COVID‑19 Vaccine for the
prevention of COVID-19, as described in the Scope of Authorization section of this letter
(Section II) and subject to the terms of this authorization. Additionally, as specified in
subsection III.BB, I am authorizing use of Pfizer-BioNTech COVID‑19 Vaccine and of
COMIRNATY (COVID-19 Vaccine, mRNA) under this EUA when used to provide: a two-dose
regimen for individuals aged 12 through 15 years; a third dose to individuals 12 years of age or
older who have undergone solid organ transplantation or who are diagnosed with conditions that
are considered to have an equivalent level of immunocompromise; or a single booster dose at
least 6 months after completing the primary series to individuals: 65 years of age and older; 18
through 64 years of age at high risk of severe COVID-19; and 18 through 64 years of age whose
frequent institutional or occupational exposure to SARS-CoV-2 puts them at high risk of serious
complications of COVID-19 including severe COVID-19."
If I'm interpreting this right:
- the existing vaccine is still available under emergency use authorization.
- a different vaccine called COMIRNATY was approved.
I didn't understand from FDA's letter if COMIRNATY exists.