I don't know what the test protocol was for AZ's Phase III tests, but per their protocols, Pfizer's vaccine was tested with participants age 16 and older, and Moderna's with participants age 18 and older.
So these are new tests, though Moderna started a Phase 2/3 test with youths age 12 to 18 back on December 10th.
Because AZ's vaccine does very poorly against the South African SARS-CoV-2 variant, I would be mildly surprised if AZ requests EUA from the US FDA for its current vaccine. If they do, I would be quite surprised if the FDA gave EUA approval. While the Pfizer, Moderna, and J & J vaccines have reasonable effectiveness against known major variants, AZ's has a significant deficiency.
J & J's (Janssen's) vaccine has not yet been approved. J & J submitted their request for EUA on February 4th, and in its usual display of urgency, the FDA committee will consider the request 3 weeks later.
. Currently US injections numbers are 21M-22M below the number of doses Pfizer and Moderna have delivered to states. When J & J receives EUA that causes a 100M dose, with options, purchase contract to go into effect. So that 21M-22M backlog in storage is likely to grow significantly.
Novavax looks to be just a few weeks behind J & J, and if/when they receive EUA, that triggers another 100M dose, with options, purchase contract. Like Pfizer's and Moderna's, the J & J and Novavax purchase contracts were negotiated during Trump's Administration. The appearance, IMO, is that Trump knew vaccines would be approved one by one, several weeks or months apart, and set up the contracts based on the expectation that states' distribution systems would correspondingly grow in volume. Yeah ... key states aren't improving very fast.
