Department of Applied Mathematics, Hong Kong Polytechnic University, Hong Kong, China.
Research Institute for Future Food, The Hong Kong Polytechnic University, Hong Kong, China.
BMC Public Health. 2023 Mar 17;23(1):511. doi: 10.1186/s12889-023-15431-2.
The high immune evasion ability of SARS-COV-2 Omicron variant surprised the world and appears to be far stronger than any previous variant. Previous to Omicron it has been difficult to assess and compare immune evasion ability of different variants, including the Beta and Delta variants, because of the relatively small numbers of reinfections and because of the problems in correctly identifying reinfections in the population. This has led to different claims appearing in the literature. Thus we find claims of both high and low immune evasion for the Beta variant. Some findings have suggested that the Beta variant has a higher immune evasion ability than the Delta variant in South Africa, and others that it has a lower ability.
In this brief report, we re-analyse a unique dataset of variant-specific reinfection data and a simple model to correct for the infection attack rates of different variants.
We find that a model with the Delta variant having an equal or higher immune evasion ability than Beta variant is compatible with the data.
We conclude that the immune evasion ability of Beta variant is not stronger than Delta variant, and indeed, the immune evasion abilities of both variants are weak in South Africa.
SARS-COV-2 奥密克戎变异株的高免疫逃逸能力令人惊讶，似乎比以往任何变异株都要强得多。在奥密克戎变异株出现之前，由于再感染的病例相对较少，以及在人群中正确识别再感染的问题，评估和比较不同变异株的免疫逃逸能力一直很困难。这导致文献中出现了不同的说法。因此，我们发现β变异株和德尔塔变异株的免疫逃逸能力都有高有低。一些研究结果表明，β变异株在南非的免疫逃逸能力高于德尔塔变异株，而另一些研究结果则表明其能力较低。
在这份简短的报告中，我们重新分析了一组独特的变异特异性再感染数据和一个简单的模型，以纠正不同变异株的感染发病率。
我们发现，一个假设德尔塔变异株的免疫逃逸能力与β变异株相等或更高的模型与数据是一致的。
我们的结论是，β变异株的免疫逃逸能力并不强于德尔塔变异株，事实上，这两种变异株在南非的免疫逃逸能力都很弱。
