Probably means the "NIH spike" updated with Omicron genes (or parts of them? I don't know for sure.) The "NIH spike" is "full-length ... pre-fusion stabilised conformation variant (K986P and V987P) of the SARS-CoV-2 (severe acute respiratory syndrome 2, GenBank: MN908947.3) spike (S) glycoprotein" according to the WHO. It is used by all current US vaccines, including NovaVax. I know Pfizer does other things to the "NIH spike" gene, including codon optimization, flanking 5 and 3 prime untranslated regions, 3 prime poly(A) tail, with all uridine replaced with N1-methylpseudouridine. They also have the secret lipid nanoparticle formulation, that not even the FDA advisors know about.