Researcher Denis Rancourt says we're still in the infancy of understanding what these shots can do to cancer progression. Common cancers are hard to isolate as a signal because their volume makes any shift difficult to detect. But rare cancers, ones that have stayed flat for years, are different. A spike in those would be a real signal.

Rancourt points to multiple primary tumors, of different origin, occurring simultaneously on different organs in the same person. He says the increase in this specific cancer type is significant in the 25-to-44 age group in the US, and shows the same sudden jump in the 75-plus age group.

Del says this data is landing right on target now, cancer types spiking as the vaccine rolled out. This isn't guesswork anymore.

@delbigtree