Department of Decision Sciences, University of South Africa, Pretoria, South Africa.
Department of Mathematics, University of Cape Coast, Cape Coast, Ghana.
PLoS Comput Biol. 2024 Oct 23;20(10):e1012456. doi: 10.1371/journal.pcbi.1012456. eCollection 2024 Oct.
The rapid development of vaccines to combat the spread of COVID-19, caused by the SARS-CoV-2 virus, is a great scientific achievement. Before the development of the COVID-19 vaccines, most studies capitalized on the available data that did not include pharmaceutical measures. Such studies focused on the impact of non-pharmaceutical measures such as social distancing, sanitation, use of face masks, and lockdowns to study the spread of COVID-19. In this study, we used the SIDARTHE-V model, an extension of the SIDARTHE model, which includes vaccination rollouts. We studied the impact of vaccination on the severity of the virus, specifically focusing on death rates, in African countries. The SIRDATHE-V model parameters were extracted by simultaneously fitting the COVID-19 cumulative data of deaths, recoveries, active cases, and full vaccinations reported by the governments of Ghana, Kenya, Mozambique, Nigeria, South Africa, Togo, and Zambia. Using South Africa as a case study, our analysis showed that the cumulative death rates declined drastically with the increased extent of vaccination drives. Whilst the infection rates sometimes increased with the arrival of new coronavirus variants, the death rates did not increase as they did before vaccination.
疫苗的快速发展是对抗由 SARS-CoV-2 病毒引起的 COVID-19 传播的一项重大科学成就。在 COVID-19 疫苗开发之前，大多数研究都利用了不包括药物措施的现有数据。这些研究主要关注非药物措施（如社交距离、卫生、使用口罩和封锁）对 COVID-19 传播的影响。在这项研究中，我们使用了 SIDARTHE-V 模型，这是 SIDARTHE 模型的扩展，其中包括疫苗接种的推广。我们研究了疫苗接种对病毒严重程度的影响，特别是在非洲国家的死亡率方面。通过同时拟合加纳、肯尼亚、莫桑比克、尼日利亚、南非、多哥和赞比亚政府报告的 COVID-19 死亡、康复、活跃病例和全面疫苗接种的累积数据，提取了 SIRDATHE-V 模型参数。利用南非作为案例研究，我们的分析表明，随着疫苗接种力度的增加，累计死亡率急剧下降。虽然感染率有时会随着新的冠状病毒变体的出现而上升，但死亡率并没有像接种疫苗前那样上升。
