Is there a list of all known antigens for pathogens and the amino acid sequence for the proteins? If so, why doesn't someone just take that list, create the peptide in an automatic synthesizer, put the peptide into the syringe and activate the immune system by injecting it? Would it work? If you knew how many proteins you were synthesizing, you can then precisely control the dose given of the antigen. How many peptides on average does an antigen need to be before it will be recognized? Of course our current technology won't allow for efficient synthetic synthesis of long peptides, but it did in the future, could we easily create pseudo vaccines from synthetic antigens?