Okay. What steps were skipped to make this happen, and why is this not done for other life-saving vaccines?
None were skipped.
Pfizer Phase 1/2 start, April 29, 2020:
https://www.pfizer.com/news/press-release/press-release-detail/biontech-and-pfizer-announce-completion-dosing-first-cohortPfizer Phase 2/3 start, July 27, 2020:
https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-choose-lead-mrna-vaccine-candidate-0Pfizer Phase 1/2 data posted July 1, 2020:
https://www.medrxiv.org/content/10.1101/2020.06.30.20142570v1Pfizer Phase 3 data published December 10, 2020 in NEJM:
https://www.nejm.org/doi/full/10.1056/NEJMoa2034577When Trump declared a Public Health Emergency (January 2020?), that made (future) Covid vaccines eligible for Emergency Use Authorization. The Trump Administration also began working with vaccine developers from January 2020 onward (months before the announcement of Operation Warp Speed).
The chosen developers/technologies have a shorter development time, because they do not need to culture the target virus and figure out how to inactivate it while keeping the inactivated viruses intact enough to be recognized as a thread by vaccine recipients' immune systems. Using Moderna as an example, Moderna was producing samples of their vaccine for lab testing a week or more before the end of January 2020. That is why Moderna was able to begin testing with humans in March 2020 (and Pfizer in April 2020). Choosing vaccine technologies that use the DNA sequence of the virus - mRNA and viral vector - was a key choice that drastically reduced development time.
The FDA handled Covid vaccines via an expedited process (the status has a name, is used for other meds, but I can't recall that official name). OWS provided funding for some vaccines' testing, making the testing less dependent on the pharma companies' ability to fund, and the contracts with the several companies signed in July and August 2020 further reduced companies' financial risk in proceeding with testing and producing millions of doses in advance of EUA.
That may be TMI, but the point is that doing this "for other life-saving vaccines" is possible, but not a trivial effort.
The FDA’s full approval of Pfizer’s shot ... is based on a study involving over 44,000 people for six months
Sloppy reporting. Since Pfizer's Phase 2/3 test began in July last year, and receiving EUA was predicated on having 2 months of data on the last person in the test to be fully vaccinated, the December 2020 EUA means that the FDA now has 10 months of data for that last person fully vaccinated, and 12 -13 months of data for the first persons fully vaccinated.