Public Health Pharmacology: a framework for population-level immunologic monitoring (PLIM) to optimize vaccine performance in Africa.

Despite high administrative immunization coverage across Sub-Saharan Africa, unexpected infectious disease outbreaks pose significant public health challenges. Traditional tracking relies heavily on logistical inputs and reactive surveillance, leaving an unmonitored biological gap in real-world host immunity. This paper presents a novel systems-design conceptual framework for Population-Level Immunologic Monitoring (PLIM) as a core operational tool of Public Health Pharmacology (PHP) to systematically bridge this gap. PLIM operates across three interconnected pillars: (1) biological sentinel surveillance using field-stabilized samples, (2) risk stratification mapping the climatic-biological nexus, and (3) near-real-time policy feedback via digital health infrastructure. To demonstrate operational plausibility, we describe a prospective "Pathfinder Pilot" validation roadmap in Rwanda. This theoretical proof-of-concept model details a logistics blueprint utilizing Dried Blood Spot (DBS) sampling paired with quantitative ELISAs and T-cell Activation Assays (TASA) integrated into existing DHIS2 software to monitor population cohorts against the Population Immunologic Threshold (PIT)-a composite metric linking individual correlates of protection to herd immunity thresholds. Crucially, PLIM complements existing administrative tracking, pharmacovigilance, and epidemiological outbreak investigations. By isolating biological host factors, the framework provides an intermediate biological audit layer. This empowers public health managers to detect waning immunity and map "biological cold spots" before outbreaks occur, advancing immunologic equity across resource-limited settings.