ABSTRACT The SARS-CoV-2 reference spike glycoprotein (Wuhan-Hu-1, YP_009724390.1)—the sole antigen in mRNA vaccines administered to billions of individuals—was not derived from a purified virion but was assembled in silico by Wu et al. (2020) from fragmented RNA in bronchoalveolar lavage fluid using Trinity and MEGAHIT without exclusion of human references or plaque purification. This study demonstrates that 32% (416 of 1273 amino acids) of this computationally generated spike consists of extended, functionally conserved segments of human proteins—including HERV-K envelope, ZAP-L zinc-finger, MSH3, collagen, and glycolytic enzyme motifs—precisely distributed across all six canonical domains previously rendered modular and swappable in a 15-year NIH/NIAID-funded chimeric coronavirus program led by Ralph Baric (16 pre-2020 publications) and explicitly claimed in US patent 9,884,895 B2 (2018) for substitution “from any source.” Parallel work by Paul Bieniasz (2005–2025) established that modern humans encode multiple full-length, infectious HERV-K envelope proteins and perfected pipelines for retroviral glycoprotein humanization and immune evasion—capabilities mirrored by the human-mosaic domains now present in the SARS-CoV-2 spike. None of these human segments occur in bat or pangolin sarbecoviruses, and their joint probability of random occurrence is conservatively estimated at <10⁻²⁰ (Fleetwood, 2025). The un-blinded assembly protocol employed by Wu et al. would be expected to maximize incorporation of abundant human transcripts into the longest computationally plausible viral open reading frame. The resulting molecule is biologically indistinguishable from a synthetic human–coronavirus chimera produced on the documented, patented platform. The evidence presented raises four unresolved scientific and ethical questions that warrant immediate independent investigation: 1) Is the reference spike most parsimoniously explained as a modular human–coronavirus chimera produced by application of pre-existing, patented technology? 2) Did the documented un-blinded assembly methodology necessarily maximize incorporation of functional human protein segments into each pre-engineered domain? 3) Is the 32% human-mosaic spike biologically distinguishable from the chimeras generated by the Baric and Bieniasz laboratories over the preceding two decades? 4) Why was an in silico antigen—never isolated from a physical virion and built on a platform explicitly designed for domain substitution from any source—selected as the template for global diagnostics and mRNA vaccination? Keywords: SARS-CoV-2, spike protein, in silico assembly, chimeric coronavirus, human-derived mosaic, human endogenous retrovirus (HERV), HERV-K, gain-of-function, reverse genetics, US9884895B2, Ralph Baric, Paul Bieniasz, de novo assembly, SRR10971381, no viral isolate, mRNA vaccine antigen, Moderna, Pfizer, furin cleavage site, synthetic biology, biosafety