It's because of how the clinical trial was designed; with the 5-11 cohort phased in first before younger groups.
"For the first phase of the trial, the companies will identify the preferred dosing level for three age groups – between 6 months and 2 years old, 2 and 5, and from ages 5 through 11. The doses will be evaluated in children ages 5 through 11 first before researchers move on to the other age groups, they said.
Because the companies are evaluating the older age group first, it’s possible data on kids under age 5 could come “a bit later,” Tureci told CNBC
So Pfizer-BioNTech can request emergency use authorization from the FDA for that 5-11 age group when the data is available (end of summer).
And in practice, the FDA will fast-track that evaluation,
per CNN, referring to the 12-15 request.
The FDA probably won't ask its Covid-19 vaccine advisory committee to weigh in on the request, the acting chairman of that committee said earlier. "They're not going to have advisories every time they tweak things," Dr. Arnold Monto said.
The
FDA issues a revision to the existing Emergency Use Authorization.