Nonlinear Dynamics and Mathematical Application Center, Kyungpook National University, Daegu, Republic of Korea.
Department of Statistics, Kyungpook National University, Daegu, Republic of Korea.
Front Public Health. 2024 Jul 3;12:1353441. doi: 10.3389/fpubh.2024.1353441. eCollection 2024.
The COVID-19 pandemic has profoundly impacted global health systems, requiring the monitoring of infection waves and strategies to control transmission. Estimating the time-varying reproduction number is crucial for understanding the epidemic and guiding interventions.
Probability distributions of serial interval are estimated for Pre-Delta and Delta periods. We conducted a comparative analysis of time-varying reproduction numbers, taking into account population immunity and variant differences. We incorporated the regional heterogeneity and age distribution of the population, as well as the evolving variants and vaccination rates over time. COVID-19 transmission dynamics were analyzed with variants and vaccination.
The reproduction number is computed with and without considering variant-based immunity. In addition, values of reproduction number significantly differed by variants, emphasizing immunity's importance. Enhanced vaccination efforts and stringent control measures were effective in reducing the transmission of the Delta variant. Conversely, Pre-Delta variant appeared less influenced by immunity levels, due to lower vaccination rates. Furthermore, during the Pre-Delta period, there was a significant difference between the region-specific and the non-region-specific reproduction numbers, with particularly distinct pattern differences observed in Gangwon, Gyeongbuk, and Jeju in Korea.
This research elucidates the dynamics of COVID-19 transmission concerning the dominance of the Delta variant, the efficacy of vaccinations, and the influence of immunity levels. It highlights the necessity for targeted interventions and extensive vaccination coverage. This study makes a significant contribution to the understanding of disease transmission mechanisms and informs public health strategies.
COVID-19 大流行深刻影响了全球卫生系统，需要监测感染浪潮并制定控制传播的策略。估计时变繁殖数对于了解疫情和指导干预措施至关重要。
估计了 Pre-Delta 和 Delta 时期的序列间隔概率分布。我们考虑了人口免疫力和变体差异，对时变繁殖数进行了比较分析。我们将人口的区域异质性和年龄分布以及随时间演变的变体和疫苗接种率纳入其中。分析了变体和疫苗接种对 COVID-19 传播动态的影响。
计算了考虑和不考虑基于变体的免疫力的繁殖数。此外，繁殖数的值因变体而异，这强调了免疫力的重要性。增强疫苗接种力度和严格控制措施可有效降低 Delta 变体的传播。相比之下，由于疫苗接种率较低，Pre-Delta 变体似乎较少受到免疫力水平的影响。此外，在 Pre-Delta 时期，区域特异性和非区域特异性繁殖数之间存在显著差异，韩国的江原道、庆尚北道和济州道的模式差异尤为明显。
本研究阐明了 COVID-19 传播的动力学，涉及 Delta 变体的主导地位、疫苗接种的效果以及免疫力水平的影响。它强调了需要进行有针对性的干预和广泛的疫苗接种覆盖。本研究对理解疾病传播机制做出了重大贡献，并为公共卫生策略提供了信息。
