Wikipedia: Operation Warp Speed (OWS) was a public–private partnership initiated by the United States government to facilitate and accelerate the development, manufacturing, and distribution of COVID-19 vaccines, therapeutics, and diagnostics.
Quoting Sasha Latypova: Two government entities became one in April 2020 because... Acting as separate federal agencies within the limits of their authorities, neither HHS nor DOD would have been able to order 100 million doses of unapproved, untested, previously thoroughly failed “vaccine." So they “partnered” in order to break the constraints of their authorities.
We have separate branches of government and separate federal agencies for many reasons. Importantly, this was envisioned by the framers as a system where federal agencies’ authorities are limited, and where different branches of government serve as checks or limits to each other. All those reasons apparently could be disregarded seemingly in an instant, under a manufactured “emergency."
Read more here.