Active safety surveillance plays a vital role in ensuring the safety of vaccines and medicines after they are approved and introduced into clinical use. This is especially important in low- and middle-income countries, where many new or high-priority products are deployed early and at large scale. A recent systematic review evaluated evidence from more than four hundred published studies across ninety-six countries and provided a comprehensive overview of how active safety surveillance is being implemented, the progress achieved so far, and the challenges that still need attention.
Active surveillance differs from routine passive reporting because it proactively seeks information on adverse events. Instead of relying on spontaneous reports from healthcare professionals or patients, active systems follow up with individuals, collect standardized information, and provide more complete and reliable safety data. The methods used include prospective and retrospective cohort studies, cohort event monitoring, pregnancy exposure registries, and digital reporting platforms. These approaches allow a better understanding of the real-world safety of vaccines and medicines and help identify safety issues early.
The review revealed that active safety surveillance has been conducted in a wide range of countries including India, China, Brazil, Ethiopia, and Uganda, with most studies focusing on vaccines such as COVID-19, measles-mumps-rubella, polio, and influenza. Others concentrated on medicines used to treat major public health problems like HIV, tuberculosis, and malaria. The COVID-19 pandemic played a major role in increasing surveillance activities and publications, particularly during and after 2020, as countries worked to monitor new vaccines and expand digital tools to record and track adverse events.
A number of strengths were observed across the reviewed articles. Many studies reported large sample sizes, effective follow-up approaches, and strong collaborations between governments, public health programs, academic institutions, and international partners. In addition, one third of the articles described using mobile tools, apps or electronic forms for data entry, follow-up, or reporting, reflecting the growing adoption of digital health technologies in these settings.
However, important challenges remain. Many active surveillance initiatives rely on short-term funding, lack sustainability, or work with limited staff and infrastructure. Several countries also face difficulties with integrating digital tools, harmonizing reporting methods, and applying standardized case definitions such as those recommended globally for vaccine safety evaluation. Only a minority of surveillance systems were considered flexible enough to rapidly incorporate new vaccines, which is a concern in contexts where new products are expected to be introduced frequently.
The review highlights the need for stronger digital platforms, better coordination between countries, and wider adoption of global safety standards to ensure comparable and higher quality data. It also emphasizes that pharmaceutical industry participation, multi-sector collaborations, and long-term national investment are essential to support broader and more sustainable surveillance programs. Strengthening active safety surveillance will not only contribute to safer immunization and treatment practices, but also help countries respond more effectively during public health emergencies and future pandemics.
Overall, the findings indicate encouraging progress in active safety surveillance across low- and middle-income countries, while drawing attention to continuing gaps. Improving digital readiness, increasing sustainable funding, promoting standardized approaches, and expanding cross-country cooperation will be central to building stronger, more reliable monitoring systems. As global health continues to evolve, such advancements are crucial for protecting communities and ensuring confidence in vaccines and medical therapies.
Learn more: SpringerSystematic Review of Active Safety Surveillance of Vaccines and Medicines in Low- and Middle-Income Countries
