Severe acute respiratory syndrome coronavirus 2 Alpha and Beta variants became dominant in Finland in spring 2021 but had diminished by summer. We used phylogenetic clustering to identify sources of spreading. We found that outbreaks were mostly seeded by a few introductions, highlighting the importance of surveillance and prevention policies.

中文翻译：

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SARS-CoV-2 Alpha 和 Beta 变体的发病趋势，芬兰，2021 年春季

严重急性呼吸系统综合症冠状病毒 2 Alpha 和 Beta 变体于 2021 年春季在芬兰占据主导地位，但到夏季有所减少。我们使用系统发育聚类来识别传播来源。我们发现疫情主要是由少数介绍引起的，这凸显了监测和预防政策的重要性。