The COVID-19 pandemic has disrupted the delivery of immunisation services globally. Many countries have postponed vaccination campaigns out of concern about infection risks to the staff delivering vaccination, the children being vaccinated, and their families. The World Health Organization recommends considering both the benefit of preventive campaigns and the risk of SARS-CoV-2 transmission when making decisions about campaigns during COVID-19 outbreaks, but there has been little quantification of the risks. We modelled excess SARS-CoV-2 infection risk to vaccinators, vaccinees, and their caregivers resulting from vaccination campaigns delivered during a COVID-19 epidemic. Our model used population age structure and contact patterns from three exemplar countries (Burkina Faso, Ethiopia, and Brazil). It combined an existing compartmental transmission model of an underlying COVID-19 epidemic with a Reed-Frost model of SARS-CoV-2 infection risk to vaccinators and vaccinees. We explored how excess risk depends on key parameters governing SARS-CoV-2 transmissibility, and aspects of campaign delivery such as campaign duration, number of vaccinations, and effectiveness of personal protective equipment (PPE) and symptomatic screening. Infection risks differ considerably depending on the circumstances in which vaccination campaigns are conducted. A campaign conducted at the peak of a SARS-CoV-2 epidemic with high prevalence and without special infection mitigation measures could increase absolute infection risk by 32 to 45% for vaccinators and 0.3 to 0.5% for vaccinees and caregivers. However, these risks could be reduced to 3.6 to 5.3% and 0.1 to 0.2% respectively by use of PPE that reduces transmission by 90% (as might be achieved with N95 respirators or high-quality surgical masks) and symptomatic screening. SARS-CoV-2 infection risks to vaccinators, vaccinees, and caregivers during vaccination campaigns can be greatly reduced by adequate PPE, symptomatic screening, and appropriate campaign timing. Our results support the use of adequate risk mitigation measures for vaccination campaigns held during SARS-CoV-2 epidemics, rather than cancelling them entirely.

中文翻译：

---

开展儿童疫苗接种活动期间的 SARS-CoV-2 感染风险：一项建模研究

COVID-19 大流行扰乱了全球免疫服务的提供。出于对接种疫苗工作人员、接种疫苗的儿童及其家人的感染风险的担忧，许多国家推迟了疫苗接种活动。世界卫生组织建议在就 COVID-19 爆发期间的运动做出决定时，同时考虑预防运动的益处和 SARS-CoV-2 传播的风险，但几乎没有对风险进行量化。我们模拟了在 COVID-19 流行期间开展的疫苗接种活动对接种者、接种者及其护理人员造成的过度 SARS-CoV-2 感染风险。我们的模型使用了来自三个示例国家（布基纳法索、埃塞俄比亚和巴西）的人口年龄结构和联系方式。它将潜在的 COVID-19 流行病的现有隔间传播模型与接种者和接种者的 SARS-CoV-2 感染风险的 Reed-Frost 模型相结合。我们探讨了超额风险如何取决于控制 SARS-CoV-2 传播性的关键参数，以及活动实施的各个方面，例如活动持续时间、疫苗接种次数以及个人防护设备 (PPE) 和症状筛查的有效性。感染风险因开展疫苗接种活动的环境而有很大差异。在 SARS-CoV-2 流行高峰期开展的高流行率且没有特殊感染缓解措施的运动可能会将接种者的绝对感染风险增加 32% 至 45%，将接种者和护理人员的绝对感染风险增加 0.3% 至 0.5%。但是，这些风险可以降低到 3.6 到 5.3% 和 0.1 到 0。通过使用可将传播减少 90% 的个人防护装备（使用 N95 呼吸器或高质量外科口罩可能实现）和对症筛查，分别降低 2%。通过适当的个人防护装备、对症筛查和适当的运动时机，可以大大降低接种者、接种者和护理人员在疫苗接种运动期间感染 SARS-CoV-2 的风险。我们的结果支持在 SARS-CoV-2 流行期间开展的疫苗接种活动中使用适当的风险缓解措施，而不是完全取消它们。和适当的竞选时机。我们的结果支持在 SARS-CoV-2 流行期间开展的疫苗接种活动中使用适当的风险缓解措施，而不是完全取消它们。和适当的竞选时机。我们的结果支持在 SARS-CoV-2 流行期间开展的疫苗接种活动中使用适当的风险缓解措施，而不是完全取消它们。