In May, researchers reported something that would have sounded like science fiction a generation ago. In patients with high-risk melanoma, an experimental mRNA cancer therapy paired with an immunotherapy drug cut the risk of the cancer returning or killing them by nearly half. The same approach is now in late-stage trials for lung, kidney, and bladder cancer. The technology behind it is the very same messenger RNA platform that produced the COVID-19 vaccine.

That shared lineage matters more than most people realize. The legal rules written for vaccines also apply to cancer therapies built on the same platform. So, a fight over vaccine liability is really a fight over something bigger: whether the next cancer breakthrough ever gets developed in the United States, and whether the public will be able to access the treatments once they’re made.