RE:Engineered (modified) OV face significant development issuesAnd this is also an issue with mRNA vaccines since the process of developing an mRNA for cancer patients would involve sequencing a patient's tumour, picking out proteins that are most likely to stimulate an immune response, making mRNAs out of those proteins and jabbing them into arms in the hopes of activating the patient's T cells. However this bespoke process of developing a personalized vaccine that is not the same for each patient is no easy task and neither would be the process of scaling production of such a personalized vaccine to the larger population that is comprised of a multitude of cancers. In other words, a mRNA vaccine must be custom made for each patient and the economies of scale would be a significant issue in the commercialization of the product to the general population, if it were ever developed.
No easy task indeed, since the cancer cells that make up tumors are usually studded with a variety of different proteins, making it extremely difficult to make a mRNA vaccine (or engineered virus) that targets all of the cancer cells and no healthy tissues.
This notwithstanding, the rapid development and roll-out of the Covid-19 vaccine has helped medicine regulatory bodies work out how to approve vaccine,s and by this virtue alone, would therefore apply to the speedy approval of oncolytic viruses, like ONCY's pelareorep, for the treatment of multiple cancers.