Medical Research Council Unit, The Gambia at London School of Hygiene and Tropical Medicine, Fajara, Banjul, The Gambia.
Malaria Genomic Epidemiology Network, Nigeria, Nigerian Institute of Medical Research, Lagos, Nigeria.
Pan Afr Med J. 2022 Feb 18;41:148. doi: 10.11604/pamj.2022.41.148.31620. eCollection 2022.
The reduction in the severity and prevalence of COVID-19 has been largely due to the rapid development and deployment of COVID-19 vaccines. Consequently, WHO, in partnership with the Coalition for Epidemic Preparedness Innovation, GAVI, the Vaccine Alliance, set up the COVID-19 Vaccines Global Access (COVAX) Initiative. The goal of this initiative is to prevent discrimination between high and low-income/middle-income countries and ensure equitable vaccine distribution. The first COVID-19 vaccine sent to most countries in the region through the COVAX initiative was the Oxford AstraZeneca (ChAdOx1 nCoV-19) vaccine. Due to the reduced protection against variants of concern, safety issues, and supply challenges of the AstraZeneca vaccine in some countries, heterologous booster dose with alternative vaccines for individuals who have received a prime dose of AstraZeneca. Moreover, vaccine mixing (heterologous vaccination) due to its superior immunogenicity and enhanced protection is being recommended even for individuals who are yet to be vaccinated. However, it is important that prior adoption, empirical data on immunogenicity, safety, and reactogenicity be locally generated in populations where such heterologous vaccine is to be implemented. Regrettably, such data from our search in all clinical trial databases is not ongoing in Africa as at the time of writing this manuscript. Therefore, this treatise advocates an experimental arm to generate such robust evidence. This will provide empirical evidence to guide this innovative approach aimed at ensuring equity and access to COVID-19 vaccines in LMICs, particularly countries within the African region.
COVID-19 的严重程度和流行率的降低在很大程度上要归功于 COVID-19 疫苗的快速开发和部署。因此，世界卫生组织与流行病防范创新联盟、全球疫苗免疫联盟合作，设立了 COVID-19 疫苗全球获取（COVAX）倡议。该倡议的目标是防止高收入和低收入/中等收入国家之间的歧视，确保公平分配疫苗。通过 COVAX 倡议发送到该地区大多数国家的第一种 COVID-19 疫苗是牛津阿斯利康（ChAdOx1 nCoV-19）疫苗。由于对关注变种的保护作用降低、阿斯利康疫苗在一些国家的安全性问题以及供应挑战，对于已经接种阿斯利康疫苗的人，建议使用替代疫苗进行异源加强剂量接种。此外，由于其更好的免疫原性和增强的保护作用，甚至建议尚未接种疫苗的人进行疫苗混合（异源接种）。然而，重要的是，在人群中实施这种异源疫苗之前，要在当地生成关于其免疫原性、安全性和反应原性的先行采用和经验数据。遗憾的是，在撰写本文时，我们在所有临床试验数据库中都没有搜索到来自非洲的此类数据。因此，本文主张设立一个实验性分支来生成这种强有力的证据。这将提供经验证据，以指导这一旨在确保中低收入国家（特别是非洲区域内的国家）公平获取 COVID-19 疫苗的创新方法。
