Surveillance of adverse events following immunization in the late 2010s: an overview of the importance, tools, and challenges

Immunization is one of the most effective measures to protect individuals and the population against vaccine-preventable diseases. Vaccines are safe and effective products, but like any other drug they can cause adverse events, which tend to become more visible as the diseases are controlled, eliminated, or eradicated. This study analyzed activities in the surveillance of adverse events following immunization (AEFI) based on data from the scientific literature, websites of immunization programs and health andregulatory agencies, and the authors’ expertise in the areas of immunizations and pharmacovigilance. With the increase in the number of vaccines in the basic immunization schedule and expansion of the population’s access, it has become essential to establish an efficient surveillance system for AEFI in Brazil. However, underreporting of cases in Brazil and in other countries hinders the detection of AEFI, especially rare events. Constantly updated information on vaccines’ risks and benefits allows immunization programs to provide rapid and clear responses to rumors of AEFI. This ensures the system’s reliability, especially in the face of the growing antivaccine movement and the increasing influence of social media in public opinion.

免疫接种是保护个体与人群免受疫苗可预防疾病侵害的最有效手段之一。疫苗是安全且有效的制品，但与其他药物一样，其也可能引发不良事件；随着相关疾病被控制、消除乃至根除，这类不良事件往往会愈发受到关注。本研究基于科学文献、免疫规划相关网站以及卫生与监管机构的数据，并结合作者在免疫接种与药物警戒领域的专业知识，对免疫接种后不良事件（Adverse Events Following Immunization, AEFI）的监测工作展开了分析。随着基础免疫程序中疫苗种类的增加以及人群疫苗接种可及性的扩大，在巴西建立高效的AEFI监测系统已成为当务之急。然而，巴西乃至全球其他国家普遍存在的病例漏报问题，阻碍了AEFI尤其是罕见不良事件的检出。持续更新的疫苗风险与获益相关信息，能够帮助免疫规划工作者针对AEFI相关传闻做出快速且明确的回应。此举可保障监测系统的可靠性，尤其是在反疫苗运动日益抬头、社交媒体对公众舆论的影响不断加剧的当下。