From Conventional Vaccines to Precision Vaccinology: A Critical Appraisal of Platform Innovation, Persistent Challenges and Systems-Based Approaches

Abstract

Vaccine development has moved within a single generation from an empirical craft founded on attenuation and inactivation to an engineering discipline in which antigens are stabilised atom by atom, delivery vehicles are formulated to programme defined innate pathways, and human immune responses are read out through high-dimensional molecular profiling. The rhetoric accompanying this transition frequently outpaces the evidence supporting it. This critical narrative review examines how far the shift from conventional vaccinology to precision vaccinology is justified by the available human data, and where claims of predictive and individualised immunisation remain aspirational. Literature published between 2000 and 26 July 2026 was identified through biomedical bibliographic databases, open scholarly indexes and citation tracking, supplemented by authoritative institutional sources, and appraised for design adequacy, replication, external validity and the alignment between evidence and claim. Five interlocking themes are developed: the comparative performance and unresolved liabilities of conventional, recombinant and genetic platforms; the maturation of structure-guided and computationally assisted antigen design; the determinants of inter-individual variability in vaccine response, including age, sex, comorbidity, microbiota and antigenic imprinting; the achievements and reproducibility limits of systems vaccinology; and the translation of mechanistic insight into correlates of protection, durable immunity, tolerable reactogenicity and equitable supply. The evidence is strongest for structure-based antigen design, for which prefusion stabilisation produced licensed products with demonstrated efficacy, and for platform-enabled speed of response. It is considerably weaker for individualised prediction: transcriptional signatures replicate as group-level associations across vaccines but have not been shown to guide clinical decisions, and benchmarking exercises indicate that simple demographic predictors can rival complex multi-omic models. Durability, mucosal protection and correlate definition beyond neutralising antibody remain unsolved. Precision vaccinology is best understood at present as a stratified rather than an individualised programme, and its principal near-term value lies in rational platform-population matching, mechanistically informed adjuvant selection and the design of trials capable of testing predictive claims prospectively.