A medicine may complete clinical trials with an acceptable safety profile and still reveal important risks only after thousands, or millions, of people begin using it. Approval is not the end of safety assessment. It is the point at which monitoring must expand from a controlled study population to the complexity of routine care.
The World Health Organization (WHO) defines pharmacovigilance as the science and activities concerned with detecting, assessing, understanding, and preventing adverse effects or other medicine-related problems (1). It works alongside broader post-market surveillance, which also monitors product quality, performance, and the circulation of substandard or falsified medical products.
Together, these systems answer a question that clinical trials cannot resolve alone: does a product’s benefit-risk balance remain favourable when it reaches real populations under real health-system conditions?
Approval shifts the burden of evidence
Before approval, safety evidence is generated through protocols, scheduled assessments, defined eligibility criteria, and closely monitored participants. After approval, the evidence environment changes.
Products reach older people, children, pregnant women, patients with multiple conditions, and people taking combinations of medicines that may not have been adequately represented in the original trials. Follow-up becomes less consistent. Diagnostic capacity varies. Medicines may be obtained through different supply channels or used alongside traditional and complementary products.
This transition creates a critical vulnerability. The responsibility for detecting risk shifts from a bounded research programme to a distributed system involving regulators, manufacturers, healthcare workers, patients, researchers, and public health programmes. If those actors are poorly connected, the safety picture becomes fragmented precisely when exposure is expanding.
That is Africa’s pharmacovigilance challenge: not simply too little data, but insufficient infrastructure to turn everyday treatment experience into timely regulatory intelligence.
The evidence gap is still substantial
VigiBase, the WHO global database of Individual Case Safety Reports (ICSRs), receives reports from national pharmacovigilance centres representing 99% of the world’s population. Yet only 18% of its data currently comes from low- and middle-income countries (2). This is not an Africa-specific percentage, but it shows how unevenly treatment experiences are represented in the global safety evidence base.
A study published in 2016 found that African countries had contributed 0.88% of the reports in VigiBase by September 2015. It also identified differences between African reports and those from the rest of the world in the medicines involved and the age profiles of patients (3). Reporting has expanded since then, so the figure should not be treated as a description of the present. Its central lesson, however, remains valid: a signal is difficult to detect when the population experiencing it is scarcely visible in the data.
This matters because medicines are used within distinct clinical and health-system contexts across the continent. HIV, tuberculosis, malaria, and a growing burden of non-communicable diseases often require multiple therapies. Co-infections, pregnancy, paediatric use, nutritional factors, traditional medicines, and limited access to laboratory monitoring may influence how adverse events arise, are recognised, and are managed.
The burden is not theoretical. A 2024 systematic review of 78 observational studies from 15 African countries reported a median prevalence of adverse drug events of 6.0% among hospital admissions and 7.8% during hospitalisation in general patient populations (4). The studies varied considerably, but their collective message is clear: medicine-related harm is a material patient-safety issue, not merely a regulatory concern.
Trial safety is the beginning, not the complete picture
Clinical trials are indispensable, but they are not designed to identify every rare, delayed, or context-specific risk. Their sample sizes, eligibility criteria, endpoints, and follow-up periods necessarily limit what can be observed before approval.
Post-market safety monitoring extends that evidence. Spontaneous reports can reveal suspected patterns. Active surveillance, registries, sentinel sites, cohort event monitoring, database studies, and post-authorisation safety studies can test those patterns more systematically. Product-quality surveillance can identify risks that arise not from the active ingredient itself, but from manufacturing defects, degradation, inappropriate storage, or falsification.
Pharmacovigilance should therefore not sit at the edge of clinical research strategy. The capabilities required during trials, including accurate documentation, rapid reporting, causality assessment, data review, and risk communication, remain essential after a product enters routine use.
When these capabilities disappear at study close-out, each trial leaves behind a temporary pocket of expertise rather than a stronger safety system. When they are retained at research sites and connected to national regulators, investment in trials can strengthen the wider health system.
A reporting form is not a safety system
Functional pharmacovigilance requires more than collecting adverse-event reports. It requires an operating chain from detection to decision.
Responsibilities must be established in law or regulation. National pharmacovigilance centres need trained personnel, secure data systems, and the authority to assess signals and recommend action. Regulators must be able to request further evidence, update product information, communicate risks, restrict use, or take other proportionate measures when the evidence warrants it.
Reporting must also be practical. Clinicians, pharmacists, nurses, community health workers, and patients need accessible channels for submitting suspected adverse events. Electronic and mobile tools can reduce friction, but technology alone will not solve under-reporting. People are more likely to continue reporting when they receive feedback and can see that the information informs decisions.
Spontaneous reporting remains essential, but it cannot carry the full burden. Active surveillance is particularly important for newly introduced products, vaccines, mass treatment programmes, medicines used during pregnancy, and therapies given to patients with multiple conditions.
Regional consistency is another weakness. A 2024 review found pharmacovigilance guidelines available for assessment in only seven of the 16 Southern African Development Community member states, with supporting legislation in four. Requirements for electronic case transmission, aggregate reporting, device vigilance, and risk management varied substantially (5). Harmonisation must therefore go beyond producing common documents. It must create the legal authority, workforce, financing, and operational capacity to implement them.
From funded projects to durable infrastructure
Continental initiatives offer a foundation for a more connected system. Led by the African Union Development Agency–NEPAD, the African Union Smart Safety Surveillance programme supports stronger safety surveillance through digital reporting, pooled expertise, work-sharing, and cross-country signal management (6).
Its AfriVigilance initiative is intended to bring together safety data from clinical trials, registration processes, and passive and active surveillance across participating countries. Pooling data is especially important where individual countries may receive too few reports to identify a pattern independently.
These developments are promising, but the decisive test is durability. Safety surveillance cannot depend indefinitely on time-limited projects or remain concentrated around specific products and disease programmes. Governments need to fund permanent pharmacovigilance posts, digital systems, active surveillance, analysis, and risk communication as core public-health functions.
Regional bodies can establish minimum operating standards and mechanisms for sharing scarce expertise. Manufacturers and marketing authorisation holders must meet clear reporting and risk-management obligations. Funders and research sponsors should plan for post-market evidence generation as part of product development, rather than treating it as somebody else’s responsibility after launch.
The role of clinical research networks
Clinical research networks are well placed to help connect pre-approval evidence with post-market learning.
Safety capabilities developed at trial sites can be retained and linked to national pharmacovigilance centres. Data systems can be designed for secure, standards-based exchange rather than remaining isolated within individual projects. Protocols can anticipate extended follow-up, registries, or post-authorisation studies where the risk profile warrants them.
Networks can also connect regulators, researchers, healthcare workers, communities, manufacturers, and public health programmes across countries. This matters because safety signals do not respect institutional or national boundaries. A pattern too small to detect in one setting may become visible when evidence is responsibly pooled.
For the Africa Clinical Research Network (ACRN), supporting credible research includes considering what happens after a trial closes. A full-lifecycle approach means helping to strengthen the relationships, skills, and systems that continue generating safety evidence during routine use, while remaining aligned with national and continental regulatory priorities.
The deeper issue is accountability. Introducing a product without the means to learn from its use leaves an avoidable gap between approval and protection. Africa does not only need greater access to medical innovation. It needs the infrastructure to observe that innovation, question it, and act when the evidence changes.
Trials end. The responsibility to learn from what happens next does not.
References
- World Health Organization (WHO). The importance of pharmacovigilance: safety monitoring of medicinal products. Geneva; 2002.
- Uppsala Monitoring Centre. VigiBase Search Services [Available from: https://who-umc.org/vigibase-data-access/vigibase-search-services/.
- Ampadu HH, Hoekman J, de Bruin ML, Pal SN, Olsson S, Sartori D, et al. Adverse Drug Reaction Reporting in Africa and a Comparison of Individual Case Safety Report Characteristics Between Africa and the Rest of the World: Analyses of Spontaneous Reports in VigiBase®. Drug Safety. 2016;39(4):335–45.
- Nyame L, Hu Y, Xue H, Fiagbey EDK, Li X, Tian Y, et al. Variation of adverse drug events in different settings in Africa: a systematic review. European Journal of Medical Research. 2024;29(1):333.
- Makhene NL, Steyn H, Vorster M, Lubbe MS, Burger JR. Assessment of pharmacovigilance guidelines in the Southern African Development Community: A document review. Pharmacoepidemiol Drug Saf. 2024;33(2):e5755.
- African Union Development Agency–NEPAD. African Union Smart Safety Surveillance (AU-3S) [Available from: https://www.nepad.org/microsite/african-union-smart-safety-surveillance-au-3s.