No, that's not at all what I'm referring to. Creating fusion proteins or inserting known nucleotide sequences into genomes has been performed for decades now. The Moderna and Pfizer vaccines work because we know what the sequence of the spike protein is. What science can't do at this moment in time, is to consistently create a string of nucleotides that does not occur in nature to create a protein that significantly different from any other known protein. Scientists can't just type out GATCTGATGTTAGAGAGACCGAGA...x1000, put it into a computational program and it will tell you if it will be a biologically active peptide. The closest coronavirus genome to SARS-CoV-2 differs by 4%. That may seem small, but 4% difference means there are 1200 genetic variants relative to the closest neighbor. Even a single mutation can have dramatic effects on a protein and virus. For example, a single mutation causes polio to be capable of neuroinvasive, thus causing poliomyelitis. That's the difference between the oral polio vaccine and disease causing poliovirus, one freaking nucleotide. 4% currently is the difference between a bat coronavirus and a human coronavirus that has infected millions of humans.uh, we do create proteins from engineered nucleotides all the time--It's how transgenics work. The most ubiquitous tool, GFP, is used in most transgenics to induce your target to create GFP (green fluorescent protein--originally synthesized from jelly fish) at whatever active site you targeted in that animal. Surely, those semi-famous frogs with glowing eyes don't naturally have the fluorescent protein from jelly fish without human intervention, no?
We move homologous gene regions from one creature to another all of the time, in order to make new proteins in our model critter. We can even transfer little strings of mRNA into critters (from other critters), to try and get that critter to generate that protein; in the event that we have also knocked out that same protein in the same critter (common rescue experiment to confirm function and result of your gene of interest). These are decades old tools, that aren't that different from how the Moderna and Pfizer vaccines work.
That's why Folding@Home was big for such a long-time. Science is still without the ability to fully predict what every amino acid sequence will fold into a protein. If you are going to engineer a virus, you're going to borrow sequences that are known, hence what you described for transgenics and what has been known for decades. But to create SARS-CoV-2, with 4% differences from a viral genome that has never been cultured or extensively studied under laboratory conditions, as I said, you would need SR Hadden backing a secret cabal of scientists who would have been working for years.