Liu Jing, Wei Haozhen, He Daihai
Department of Applied Mathematics, Hong Kong Polytechnic University, Hong Kong, China.
Research Institute for Future Food, The Hong Kong Polytechnic University, Hong Kong, China.
Public Health Pract (Oxf). 2023 Jun;5:100350. doi: 10.1016/j.puhip.2022.100350. Epub 2022 Dec 10.
Variants of Severe-Acute-Respiratory-Syndrome Coronavirus-2 (SARS-CoV-2) has caused tremendous impact globally. It has been widely reported that the Omicron (B.1.1.529) variant is less deadly than the Delta (B.1.617.2) variant, presumably due to immunity from vaccination and previous infection. When measuring the severity of a variant, Case-Fatality-Rate (CFR) is often estimated. The purpose of this work is to calculate the change in CFR of different variants over time from a large number of countries/regions since the start of the pandemic in 2020.
A Cross-sectional study.
We extend the comparison to all previous VOCs in 58 counties/regions. We use reported death divided by reported cases in 30-day sliding window with a two-week shift between reported death and reported cases.
The drop from Delta variant to Omicron variant is substantial and the difference between subvariants of Omicron is not evident.
We showed that the CFR dropped over time, presumably due to vaccine-induced immune and infection induced immune. Population age structure and prevalence of comorbidity influence CFR.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）变体在全球造成了巨大影响。广泛报道称，奥密克戎（B.1.1.529）变体的致死性低于德尔塔（B.1.617.2）变体，推测这是由于疫苗接种和既往感染产生的免疫力。在衡量一个变体的严重程度时，通常会估算病死率（CFR）。这项工作的目的是计算自2020年大流行开始以来，来自大量国家/地区的不同变体的CFR随时间的变化。
一项横断面研究。
我们将比较范围扩大到58个县/地区的所有先前的变异株。我们使用报告死亡数除以30天滑动窗口内的报告病例数，报告死亡数和报告病例数之间有两周的时间偏移。
从德尔塔变体到奥密克戎变体的下降幅度很大，奥密克戎亚变体之间的差异不明显。
我们表明，CFR随时间下降，推测是由于疫苗诱导的免疫和感染诱导的免疫。人群年龄结构和合并症患病率会影响CFR。
