突变使流行病变得更糟或更好:模拟SARS-CoV-2变种和不完美的疫苗接种
Sarita Bugalia1, Jai Prakash Tripathi2, Hao Wang3
1Department of Mathematics, Central University of Rajasthan, Bandar Sindri, Kishangarh, Ajmer, Rajasthan, 305817, India.
Journal of mathematical biology
|March 20, 2024
概括
这项研究以原生和突变菌株的COVID-19 (冠状病毒病2019) 传播为模型,结合了不完美的疫苗接种和突变动态. 提高针对突变菌株的疫苗疗效对于控制总病例和减少死亡人数至关重要.
科学领域:
- 传染病的流行病学和数学建模.
- 病毒学,专注于病毒突变和菌株动态.
- 公共卫生,特别是疫苗接种策略和群体免疫.
背景情况:
- COVID-19 (冠状病毒疾病2019) 是一个重要的全球健康威胁,由易发生突变的RNA病毒驱动.
- 诸如Delta和Omicron等变种的出现改变了疾病的传染性和死亡率.
- 了解病毒进化,传播和疫苗接种之间的复杂相互作用对于有效控制至关重要.
研究的目的:
- 开发和分析COVID-19传播的动态模型,考虑原生和突变菌株,突变和不完美的疫苗接种.
- 调查突变率和疫苗疗效对疾病动态的影响,包括振荡和特有状态.
- 为了获得疫苗诱导群体免疫的分析表达式,并评估其流行病学影响.
主要方法:
- 开发一个包含突变和不完美的疫苗接种的两株动态模型 (原生和突变).
- 使用中心多元理论进行数学分析,以确定稳定性和分叉性质 (例如,Hopf分叉).
- 模型的参数化使用印度COVID-19数据 (2021年3月至9月) 通过马尔科夫链蒙特卡洛 (MCMC) 方法.
- 使用拉丁式超立方体采样和部分等级相关系数的灵敏度分析.
主要成果:
- 基本繁殖数 () 被计算为原生和突变菌株繁殖数的最大值.
- 无病平衡的全球稳定性在时被证明,表明有效的菌株消除与足够的疫苗疗效.
- 霍夫分叉导致中等突变速率 () 的振荡,而更高的速率可以导致稳定 ("流行性泡").
- 提高针对突变菌株的疫苗疗效显著减少累积病例和死亡;90%的针对本地菌株的疗效减少了0.40%的病例/死亡.
- 对突变菌株的免疫力对控制总病例的影响比疫苗对它们的有效性更大.
结论:
- 该研究强调,虽然某些突变率可能导致有害的振荡 (重复爆发),但更高的突变率可能导致更稳定,更低的感染水平.
- 提高疫苗疗效,特别是针对突变菌株,是缓解COVID-19大流行的一个关键策略.
- 衍生群体免疫门为消除疾病提供了目标,强调了社区级免疫的重要性.
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