Yserbius,
my understanding – Pfizer was paying Biontech themselves. It is very typical for a large company to pay for R&D themselves and, thus, keep IP to themselves. [of course, there is also criticism of Trump for giving Phizer those rights]. This is really a manifestation of market power against a lazy customer (US government), as those R&D funds come out of profits from US customers, often regulated.
In ~ 1982, Reagan’s Sec of Navy started doing separate bids for R&D, and then use R&D results as a starting point for production bids for a small number (2-3) of available producers. Industry was not happy to lose “R&D rights”, and it worked. Clinton’s team closed some to generate saving “from duplication”. It is hit and miss from there on between two extremes – either allowing industry own everything, or taking all IP away and making industry into a disinterested manufacturer.