Abstract：
When vaccines against the novel COVID-19 were available in Senegal, many questions were raised. How long should non-pharmaceutical interventions (NPIs) be maintained during vaccination roll-out? What are the best vaccination strategies?
In this study, we used an age-structured dynamic mathematical model. This model uses parameters based on SARS-CoV-2 virus, information on different types of NPIs, epidemiological and demographic data, some parameters relating to hospitalisations and vaccination in Senegal.
In all scenarios explored, the model predicts a larger third epidemic wave of COVID-19 in terms of new cases and deaths than the previous waves. In a context of limited vaccine supply, vaccination alone will not be sufficient to control the epidemic, and the continuation of NPIs is necessary to flatten the epidemic curve. Assuming 20% of the population have been vaccinated, the optimal period to relax NPIs would be a few days from the last peak. Regarding the prioritisation of age groups to be vaccinated, the model shows that it is better to vaccinate individuals aged 5-60 years and not just the elderly (over 60 years) and those in high-risk groups. This strategy could be more cost-effective for the government, as it would reduce the high costs associated with hospitalisation. In terms of vaccine distribution, the optimal strategy would be to allocate full dose to the elderly. If vaccine doses are limited, half dose followed by full dose would be sufficient for people under 40 years because whether they receive half or full dose, the reduction in hospitalisations would be similar and their death-to-case ratio is very low.
This study could be presented as a decision support tool to help devise strategies to control the COVID-19 pandemic and help the Ministry of Health to better manage and allocate the available vaccine doses.
In this study, we used an age-structured dynamic mathematical model. This model uses parameters based on SARS-CoV-2 virus, information on different types of NPIs, epidemiological and demographic data, some parameters relating to hospitalisations and vaccination in Senegal.
In all scenarios explored, the model predicts a larger third epidemic wave of COVID-19 in terms of new cases and deaths than the previous waves. In a context of limited vaccine supply, vaccination alone will not be sufficient to control the epidemic, and the continuation of NPIs is necessary to flatten the epidemic curve. Assuming 20% of the population have been vaccinated, the optimal period to relax NPIs would be a few days from the last peak. Regarding the prioritisation of age groups to be vaccinated, the model shows that it is better to vaccinate individuals aged 5-60 years and not just the elderly (over 60 years) and those in high-risk groups. This strategy could be more cost-effective for the government, as it would reduce the high costs associated with hospitalisation. In terms of vaccine distribution, the optimal strategy would be to allocate full dose to the elderly. If vaccine doses are limited, half dose followed by full dose would be sufficient for people under 40 years because whether they receive half or full dose, the reduction in hospitalisations would be similar and their death-to-case ratio is very low.
This study could be presented as a decision support tool to help devise strategies to control the COVID-19 pandemic and help the Ministry of Health to better manage and allocate the available vaccine doses.
摘要：
当针对新型COVID-19的疫苗在塞内加尔上市时，提出了许多问题。在疫苗接种推广期间，非药物干预措施（NPI）应维持多长时间？最佳疫苗接种策略是什么？
在本研究中，我们使用了年龄结构的动态数学模型。该模型使用基于SARS-CoV-2病毒的参数，关于不同类型的NPI的信息，流行病学和人口统计数据，与塞内加尔住院和疫苗接种有关的一些参数。
在探索的所有场景中，该模型预测，在新增病例和死亡人数方面，COVID-19的第三波流行将比前几波更大。在疫苗供应有限的情况下，光靠接种疫苗不足以控制疫情,NPI的延续对于平缓疫情曲线是必要的。假设20%的人口接种了疫苗，放松NPI的最佳时期是从最后一个高峰开始的几天。关于优先考虑接种疫苗的年龄组，该模型表明，最好为5-60岁的人接种疫苗，而不仅仅是老年人（60岁以上）和高危人群。这种策略对政府来说可能更具成本效益，因为这将减少与住院相关的高昂费用。就疫苗分布而言，最佳策略是为老年人分配全剂量。如果疫苗剂量有限，对于40岁以下的人来说，半剂量后全剂量就足够了，因为无论他们接受半剂量还是全剂量，住院率的减少将是相似的,并且他们的死亡病例比非常低.
这项研究可以作为决策支持工具来帮助制定控制COVID-19大流行的策略，并帮助卫生部更好地管理和分配可用的疫苗剂量。
在本研究中，我们使用了年龄结构的动态数学模型。该模型使用基于SARS-CoV-2病毒的参数，关于不同类型的NPI的信息，流行病学和人口统计数据，与塞内加尔住院和疫苗接种有关的一些参数。
在探索的所有场景中，该模型预测，在新增病例和死亡人数方面，COVID-19的第三波流行将比前几波更大。在疫苗供应有限的情况下，光靠接种疫苗不足以控制疫情,NPI的延续对于平缓疫情曲线是必要的。假设20%的人口接种了疫苗，放松NPI的最佳时期是从最后一个高峰开始的几天。关于优先考虑接种疫苗的年龄组，该模型表明，最好为5-60岁的人接种疫苗，而不仅仅是老年人（60岁以上）和高危人群。这种策略对政府来说可能更具成本效益，因为这将减少与住院相关的高昂费用。就疫苗分布而言，最佳策略是为老年人分配全剂量。如果疫苗剂量有限，对于40岁以下的人来说，半剂量后全剂量就足够了，因为无论他们接受半剂量还是全剂量，住院率的减少将是相似的,并且他们的死亡病例比非常低.
这项研究可以作为决策支持工具来帮助制定控制COVID-19大流行的策略，并帮助卫生部更好地管理和分配可用的疫苗剂量。
