新型冠状病毒奥密克戎变异株已经成为目前流行最广的新型冠状病毒变异株，其发生在刺突蛋白上的广泛突变赋予变异株新的特性，给公共卫生安全带来了巨大挑战。此文对奥密克戎株的感染机制及部分流行病学特点、现有疫苗对奥密克戎株引发疾病的有效性分析、突破性感染风险分析、以及对疫苗改进及研发方向的展望4个方面进行了阐述。奥密克戎株进入细胞的方式从膜融合转变为内吞途径，新突变的生成赋予了该变异株传播力强、潜伏期及恢复期时间短、引起症状轻、疫苗接种及恢复期人群同样易感等特点，严重影响了疫苗有效性，增加了突破性感染的风险，对后续疫苗的改进及研发方向提出了新的要求。

Omicron variant has become the most prevalent strain of severe acute respiratory syndrome coronavirus 2. The extensive mutations in the spike protein endow the variant with new characteristics, which bring great challenges to public health. This article describes the infection mechanism and some epidemiological characteristics of Omicron variant, the effectiveness analysis of existing vaccines against Omicron-induced diseases, the risk analysis of breakthrough infections, and the prospect of vaccine improvement, research and development. The entry mode of Omicron variant has changed from membrane fusion to endocytosis pathway. The generation of new mutations endows this variant with strong transmission, short incubation period and recovery period, mild symptoms, and susceptibility to vaccination and convalescence, which seriously affects vaccine effectiveness and increases the risk of breakthrough infection. New requirements have been put forward for the future improvement, research and development of vaccines.