Kennedy · Proceedings. Biological sciences 2017 · theoretical narrative review · n=?

Why does drug resistance readily evolve but vaccine resistance does not?

Cited 200 times in the scientific literature.

Level 5 - mechanism / opinion, no new human data

Mechanism-based reasoning and evolutionary theory synthesis without original empirical data or systematic review.

PubMed 28356449 · doi:10.1098/rspb.2016.2562 · record verified 2026-08-31

What was done

Theoretical synthesis using population genetics and evolutionary ecology principles to analyze why pathogen resistance emerges readily against antimicrobial drugs but rarely against vaccines.

What was found

The abstract reports no quantitative measurements or experimental data. It outlines two primary mechanistic distinctions: vaccines generally act prophylactically (reducing pathogen load and replication potential early) and induce polyclonal immune responses against multiple pathogen epitopes, whereas drugs typically act therapeutically during high pathogen burdens and target very few specific sites. These factors reduce the generation of genetic variation and the strength of selection for vaccine escape.

Why it matters

Explains the fundamental evolutionary basis for the long-term durability of vaccines compared to therapeutic drugs, offering a framework to anticipate and identify which vaccines might be vulnerable to resistance.

Limits

The abstract describes a conceptual, narrative framework rather than a systematic review or empirical experimental study. It provides no empirical data, statistical models, or sample counts, and acknowledges that vaccine resistance can still emerge when these standard conditions are violated.

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