A new class of time series models is used to track the progress of the COVID-19 epidemic in the UK in early 2021. Models are fitted to England and the regions, as well as to the UK as a whole. The growth rate of the daily number of cases and the instantaneous reproduction number are computed regularly and compared with those produced by SAGE. The results from figures published each day are compared with results based on figures by specimen date, which may be more accurate but are subject to substantial revisions. It is then shown how data from the two different sources can be combined in bivariate models.

中文翻译：

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追踪突变体：2021 年英国的 COVID-19 预测和临近预报

一种新的时间序列模型用于跟踪 2021 年初英国 COVID-19 流行病的进展。模型适用于英格兰和各地区，以及整个英国。定期计算每日病例数和瞬时繁殖数的增长率，并与 SAGE 产生的数据进行比较。每天公布的数据结果与基于样本日期的数据结果进行比较，这可能更准确，但会进行大量修改。然后展示了如何在双变量模型中组合来自两个不同来源的数据。