Background

Serious adverse reactions after immunization are rare but do occur. In very rare instances, cases with fatal outcome have been reported. These reports can have a huge impact and even more so when due to an immunization error. The aim of this study is to systematically review immunization errors with fatal outcomes in EudraVigilance.

Methods

This was a case-series analysis of Individual Case Safety Reports (ICSRs) reporting immunization errors and a fatal outcome. To determine the level of certainty of a causal association between the immunization errors and fatal outcomes two independent reviewers assessed all ICSRs using the WHO tool “Causality assessment of an Adverse Event Following Immunization (AEFI)”. In accordance with the tool, the ICSRs were classified as consistent, indeterminate, inconsistent/coincidental, or unclassifiable. In addition, we estimated the contribution of reported errors to the fatal outcomes as large, moderate, small, none, or unclassifiable using a classification developed for this study.

Results

A total of 154 ICSRs met the inclusion criteria. Vaccines reported most frequently were pneumococcal (33), rabies (27) and influenza vaccines (24). Most frequently reported errors were non-compliance with recommended schedules of immunization (63). The most frequently reported vaccine-error combination was rabies vaccines and non-compliance with a recommended schedule of immunization (23). Twelve cases were classified as consistent with causal association and had a large error contribution. These cases concerned a cluster of six cases reporting incorrect handling of multi-dose vials containing measles vaccine and six cases reporting administration of live-attenuated vaccines to immunocompromised patients.

Discussion

In this study, we showed that fatal outcomes following immunization errors are very rare. Four key issues were the importance of: (1) quality control of multi-dose vaccines, (2) screening patients for immunocompromising factors, (3) education on the importance of adherence, and (4) measures to improve distinction between vaccines and medicines.

中文翻译：

---

向EudraVigilance报告的免疫错误后的致命结果：病例系列。

背景

免疫后严重的不良反应很少见，但确实会发生。在极少数情况下，有致命结果的报道。这些报告可能会产生巨大的影响，而由于免疫错误会产生更大的影响。这项研究的目的是系统地审查EudraVigilance中具有致命后果的免疫错误。

方法

这是对个别病例安全性报告（ICSR）的病例系列分析，报告了免疫错误和致命结果。为了确定免疫错误和致命结果之间因果关系的确定性水平，两名独立审核员使用WHO工具“免疫后不良事件的因果关系评估（AEFI）”评估了所有ICSR。根据该工具，将ICSR分类为一致，不确定，不一致/一致或无法分类。此外，我们使用针对本研究开发的分类法，估计报告的错误对致命结果的贡献为大，中，小，无或无法分类。

结果

共有154个ICSR符合纳入标准。报告最频繁的疫苗是肺炎球菌（33），狂犬病（27）和流感疫苗（24）。最常报告的错误是未遵守建议的免疫方案（63）。报告最频繁的疫苗与错误的组合是狂犬病疫苗和不符合建议的免疫接种时间表（23）。12个案例被归类为符合因果关系，并且造成很大的错误贡献。这些案例涉及六例，其中六例报告了对含麻疹疫苗的多剂量小瓶的处理不当，六例报告了对免疫功能低下的患者使用减毒活疫苗。

讨论区

在这项研究中，我们表明免疫错误导致的致命后果非常罕见。四个关键问题的重要性是：（1）多剂量疫苗的质量控制；（2）对患者进行免疫功能低下因素的筛查；（3）关于依从性重要性的教育；（4）改善疫苗与药物区别的措施。