Several important aspects related to SARS-CoV-2 transmission are not well known due to a lack of appropriate data. However, mathematical and computational tools can be used to extract part of this information from the available data, like some hidden age-related characteristics. In this paper, we present a method to investigate age-specific differences in transmission parameters related to susceptibility to and infectiousness upon contracting SARS-CoV-2 infection. More specifically, we use panel-based social contact data from diary-based surveys conducted in Belgium combined with the next generation principle to infer the relative incidence and we compare this to real-life incidence data. Comparing these two allows for the estimation of age-specific transmission parameters. Our analysis implies the susceptibility in children to be around half of the susceptibility in adults, and even lower for very young children (preschooler). However, the probability of adults and the elderly to contract the infection is decreasing throughout the vaccination campaign, thereby modifying the picture over time.

翻译：由于缺乏适当数据,与SARS-CoV-2传染有关的几个重要方面并不广为人知,然而,数学和计算工具可以用来从现有数据中提取这一信息的一部分,例如一些与年龄有关的隐蔽特征;在本文件中,我们提出一种方法,用以调查在感染SARS-CoV-2感染时,在传播参数方面与年龄有关的具体差异;更具体地说,我们利用在比利时进行的日记调查中基于小组的社会接触数据,结合下一代原则,来推断相对发病率,并将此与实际发病率数据进行比较。比较这两个工具可以用来估计特定年龄的传播参数。我们的分析表明,儿童在成人易感染性的一半左右,对于非常年幼的儿童(学龄前儿童)而言,感染的可能性甚至更低。然而,在整个疫苗接种运动中,成人和老年人感染感染的可能性正在下降,从而随着时间的推移而改变情况。