Monitoring the safety of medicines and vaccines: An essential public health service

Vaccines and medicines are indispensable for preventing infections, treating diseases, or reliving pain. But there are risks of unwanted or unexpected events that can happen from harmful interactions between a medicine and food, beverage, or another medicine, or that the medicine may not work as expected and can cause additional problems.  Continuous monitoring is therefore required for managing the benefits and risks of medicines.   

A series of World Bank case studies illustrate the importance of this often overlooked but essential public health service that is fundament to create and sustain trust in the health sector and in its institutions.

Adverse drug reactions (ADRs) pose a significant challenge to health systems worldwide

The CDC estimated that more than 1 million individuals are seen in emergency departments for ADRs each year in the United States; more than one-quarter require hospitalization for further treatment. Similarly, a European Commission report documented that 3-10 percent of hospital admissions between 2012 and 2014 were estimated to have been associated with ADRs, totaling about 2.5–8.4 million annually. In Australia, serious ADRs were associated with considerably longer hospital stays, risk of readmission, or in-hospital death.

ADRs are also an important cause of morbidity in low-and-middle income countries (LMICs). For example, a systematic review in nine African countries, found that 8.4 percent of patients reported at hospital admission to have experienced ADRs, while a study in Brazil suggested a significant association between the use of off-label drugs (medications that are used in a way that has not be approved) and the occurrence of ADRs in patients admitted in an adult intensive care unit. 

Likewise, a study in South Korea showed that ADR-related emergency department visits and hospitalizations increase national health insurance costs and out-of-pocket expenditures by patients.

Building blocks of pharmacovigilance (PV)

The World Health Organization (WHO) defines PV as “the science and activities relating to the detection, assessment, understanding and prevention of adverse effects or any other medicine/vaccine related problem.”  

WHO assessments suggest that majority of LMICs have limited institutional capacity to adequately monitor the safety of medicines when compared with the mature pharmacovigilance infrastructure in high-income countries. The experience of countries such as Korea, Brazil, and Ghana, and of regional organizations such as the European Medicines Agency and the Caribbean Public Health Agency, indicates that functioning and effective PV programs rest on five key pillars: 

1. A strong legal and institutional foundation, including a strong human resource base;
2. A nation-wide safety monitoring system;
3. A computerized system to facilitate reporting of ADRs by different sources (i.e., health professionals, healthcare facilities, patients, and pharmaceutical companies);
4. The use of PV evidence for policy making, regulatory action, risk communication, and education activities; and
5. A sustainable funding arrangement.

How can drug safety monitoring contribute to building resilient health systems?

PV supports the performance of key functions in a health system: 

• Policy making and regulation. In OECD countries, for example, regulatory agencies have used evidence from routinely collected data to confirm or counter suspected drug safety concerns, and depending on the results, it led to market withdrawal, safety notifications and labelling changes, modified indications, or confirmation of the initial terms of marketing authorization. These measures help improve how medicines are prescribed and used. Also, PV data has helped inform in some OECD countries the revision of their prices and reimbursement conditions. The surveillance of pharmaceutical pollution and the effects of drug residues in the environment, such as from antibiotics, can help adopt measures to protect the environment, human health, and livestock.
• Public health programs for disease control. In Vietnam, active TB drug-safety monitoring among patients has helped understand the safety of multidrug-resistant TB treatment, reducing inconvenience, discomfort, and toxicity of such regimens, and, increasing adherence and likelihood of successful treatment completion. PV has also been of great importance for malaria control programs due to increasing resistance to existing antimalarial medicines. Ghana’s experience shows how routine reporting of adverse events following immunization served as a cornerstone for developing a comprehensive PV program under the FDA Ghana.
• Clinical practice. PV can help improve medical care by modifying clinical guidelines based on evidence. During the first waves of COVID-19, for example, the absence of medicines and vaccines for treatment and prevention of the disease led to a rush to repurpose drugs already approved for other indications. After some adverse effects from the administration of these drugs were reported, regulatory agencies issued warnings against their use.  PV also has the potential to strengthen antimicrobial stewardship strategies by providing data on suspected resistance and inappropriate use of antibiotics.
• Risk communication. PV can support delivery of effective information, education, and communication by government officials, service providers, and pharmaceutical firms to the public. As shown during the pandemic, these activities are vital to address disinformation that hampers public health efforts, concerns and fears among the public about adverse effects of medicines, and ultimately, to save lives.

Looking ahead

PV should be seen as a ‘global public good’ whose benefits affect us all. As such, technical and financial assistance of international agencies is needed to complement country efforts to develop this capacity as part of initiatives to build resilient health systems.  In particular, support is required to assist countries leverage new technologies, such as artificial intelligence tools, that have the potential to transform safety monitoring by systematic mining and assessing large amounts of health data in real world settings. This is doable, as the results of a recent systematic review show that machine learning is already being used for this purpose.

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