Acute lymphoblastic leukaemia (ALL) is the most common type of leukaemia diagnosed in children. The prevailing hypothesis regarding pathogenesis of childhood ALL was developed by Greaves, and states that ALL is caused by an abnormal immune response to a common infection. The response arises either due to naivety of the immune system caused by a lack of common childhood infections, or genetic susceptibility due to specific alleles. The former explanation is known as the delayed infection hypothesis. COVID-19 is a new infection that no children in the UK were exposed to prior to 2020. Furthermore, the lockdown measures designed to prevent spread of this virus have also greatly reduced spread of other common infections. It is therefore important to examine the evidence for this hypothesis, and to consider it in the context of the pandemic to determine what effect lockdown measures may have on incidence of ALL in children.

中文翻译：

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白血病和封锁：儿童急性淋巴细胞白血病和 COVID-19 大流行的延迟感染模型

急性淋巴细胞白血病 (ALL) 是儿童中诊断出的最常见的白血病类型。关于儿童 ALL 发病机制的普遍假设是由 Greaves 提出的，并指出 ALL 是由对常见感染的异常免疫反应引起的。这种反应要么是由于缺乏常见的儿童感染引起的免疫系统的幼稚，要么是由于特定的等位基因引起的遗传易感性。前一种解释被称为延迟感染假说。COVID-19 是一种新的感染，在 2020 年之前，英国没有儿童接触过这种感染。此外，旨在防止这种病毒传播的封锁措施也大大减少了其他常见感染的传播。因此，检查这一假设的证据很重要，