I wonder who they stole that from?
Novamax maybe?
Protein subunit technology is a known vaccine development technique.
Rather than injecting a whole pathogen to trigger an immune response, subunit vaccines (sometimes called acellular vaccines) contain purified pieces of it, which have been specially selected for their ability to stimulate immune cells. Because these fragments are incapable of causing disease, subunit vaccines are considered very safe.
Subunit vaccines are already in widespread use. Examples include the hepatitis B and tetanus vaccines.