How to build a cancer vaccine, and whether they will work this time
The article explores recent advances in cancer vaccine development, detailing different technological approaches and clinical trials. It examines why previous cancer vaccines have failed and whether new mRNA and personalized vaccine strategies may finally prove effective against various cancer types.
Background
- Cancer vaccines differ from preventive vaccines (like HPV shots): they train the immune system to attack existing tumors, not prevent disease. The field has seen many failures over decades because tumors actively suppress immune responses and mutate rapidly.
- Recent progress stems from mRNA technology (proven in COVID vaccines) and better understanding of neoantigens — unique protein fragments on cancer cells that can serve as vaccine targets personalized to each patient's tumor.
- Key companies in the space include Moderna (mRNA-4157, in Phase 2/3 trials with Merck), BioNTech (BNT122 for pancreatic cancer, in Phase 2), and Gritstone Bio (self-amplifying RNA). All three reported encouraging early data in 2023.
- A major open question is whether these vaccines will work against advanced, heavily pretreated cancers or only in earlier-stage, minimal-residual-disease settings. The article critically examines that divide.