They still benefitted from decades of basic research paid for by the government. They also benefitted by having signed POs before starting phase 3 trials.
The US government paid for the research in how to make a coronavirus vaccine starting in 2003, without that there would be no COVID vaccine right now.
Remember, Pfizer's research was actually carried out by BioNTech in Germany, not Pfizer in the U.S.
The P.O.'s are pointless as the fact remains...when the vaccine was approved, buyers were standing in line with contracts, so the fact purchase orders were put in place early is rather meaningless...every drop of vaccine Pfizer/BioNTech produces will be sold immediately. Everyone with half a brain could and should have known this fact. And a P.O. is not cash or a payment....just a piece of paper stating someone will buy something at some future date for some price. And contracts get broken every day.
And your last assertion is conflated bullshit. Many of the technologies now used widely for vaccine design are rooted in longstanding programs to fight HIV and influenza. All of the leading vaccines are based on the SARS-COVID2 spike protein, the entity on the virus surface that drives infection of human cells. Decades of work, first on the corresponding HIV spike protein and then its counterparts from other viruses, including SARS, MERS, and seasonal coronaviruses, showed how best to design and produce the SARS-CoV-2 version.
The Pfizer/BioNTech and Moderna/NIH vaccines deliver the spike protein in the form of mRNA. This technology emerged during the past decade from university laboratories working on HIV and influenza vaccines, which then triggered Zika, Ebola, and coronavirus vaccine programs at the NIH and in the pharmaceutical industry. The Moderna mRNA vaccine, in particular, was made as a collaboration with the NIH’s Vaccine Research Center, funded by U.S. taxpayers since 1997 to create vaccines against deadly viruses and other human diseases. A method developed by Janssen, a pharmaceutical company, to present spike proteins to the immune system also emerged from an HIV vaccine program at Harvard University. AstraZeneca’s version of the adenovirus delivery system has a similar history. Decades of work on the corresponding HIV and influenza proteins, as well as coronavirus proteins, underpin the Novavax SARS-CoV-2 spike protein vaccine design. DNA vaccines are also in clinical trials, another method derived from research on HIV and other viral pathogens.
This is all said to show the assertion that the U.S. somehow single-handedly researched, developed, and sold COVID vaccines is bullshit. These vaccine developments have been funded by countries/entities worldwide, not just the U.S., and not in the last decade or two...but over decades of research built upon prior research built upon prior research. You gotta just let your jingoistic nationalism go.