The problem with mRNA vaccines for cancer is effectiveness. Vaccines already work well for prevention of relapses in e.g. tumors that have been surgically removed.

They might also be great combined with early-stage detection via ctDNA.

But in late-stage patients, the effectiveness is limited because the host immune system is compromised.

Several landmark mRNA cancer vaccine trials by BioNTech and others have pointed in this direction.

In vivo reprogramming of T cells might be the next frontier. In fact, the BioNTech founders are moving to a new venture, but it's unclear what their thesis is.

I’d be mostly concerned about testing that it dowsn’t have side effects. You probably can do a lot in vitro, but you need a platform to do it.

Given the tremendous success of the covid mRNA campaign it's surely right around the corner.