Inactivated COVID-19 vaccines developed by China curbed the spread of the Delta variant during a May outbreak in Guangzhou, a study has shown.

研究显示，中国产新冠病毒灭活疫苗在5月份广州新冠疫情暴发期间遏制了德尔塔毒株的传播。

Led by reputed Chinese epidemiologist Zhong Nanshan, researchers from the Guangzhou Center for Disease Control and Prevention found two shots of the vaccines showed an efficacy of 59% against COVID-19 caused by the Delta variant, 70.2% against moderate forms of the disease, and 100% against severe cases.

广州市疾病预防控制中心联合流行病学家钟南山团队研究发现，完整接种两剂次灭活疫苗对预防德尔塔毒株的总体保护效果达59%，对中度症状的保护率为70.2%，对重症的保护效果达100%。

According to the research paper, the protective effect of the two-dose vaccination against the Delta strain reached 72.5% among study participants aged 40 to 59.

研究报告指出，在40岁至59岁的研究参与者中，接种两剂次灭活疫苗对预防德尔塔毒株的总体保护效果达72.5%。

Vaccine efficacy was also higher in females.

在女性群体中，灭活疫苗的保护效果也更高。

Meanwhile, with an efficacy of only 13.8%, one dose of vaccine did not provide sufficient protection.

研究还发现，仅接种一剂次灭活疫苗不能产生有效的保护效果(13.8%)。