Clinical trial phases (I / II / III)
The staged path a vaccine takes from first-in-human safety to large efficacy trials — the timeline that gates whether a method ever reaches patients.
Phase I tests safety and dose in a small group; phase II looks for early efficacy signals and immune response in a larger one; phase III is the large, often randomized trial that must show real clinical benefit (e.g. longer recurrence-free survival) for approval. Personalized vaccines also live or die on a practical axis trials must prove out: manufacturing turnaround per patient.
For reading the digest: a striking algorithmic result is still pre-clinical until it shows up as an immune response or survival benefit in a trial. Knowing the phase tells you how much to weight a headline — phase I immunogenicity is a hint; phase III survival data is the thing the whole field is trying to move.