Boum Yap, Matchim Lucrece, Guimsop Dominique K, Buri Bongkiyung D, Bebell Lisa M, Jaudel Yuya S F, Njuwa Fai K G, Danirla Daniel B, Youm Eric, Ntone Rodrigue, Tchame Claudric Roosevelt, Tchiasso Dora, Essaka Rachelle, Eyong Justin B, Ngosso Audrey, Nanda Herwin, Fondze Nsaibirni R, Ndifon Mark Ndifon, Eteki Lucrèce, Ghislain Yonta F C, Messi Bruno Yannick Eyenga, Moustapha Hamadou, Hamdja Moustafa, Essomba René Ghislain, Mandeng Nadia, Modeste Tamakloe A K, Bisseck Anne-Cécile Zoung-Kani, Eyangoh Sara Irène, Njouom Richard, Okomo Marie Claire, Esso Linda, Emilienne Epee, Mballa Georges-Alain Etoundi
Public Health Emergency Operation Center, Ministry of Public Health, Yaoundé, Cameroon.
Epicentre, Yaoundé, Cameroon.
J Public Health Afr. 2024 Nov 7;15(1):649. doi: 10.4102/jphia.v15i1.649. eCollection 2024.
Little is known about the evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity in African communities.
We evaluated changes in anti-SARS-CoV-2 antibodies, mortality and vaccination status in Cameroon between August 2021 and September 2022 to begin describing the evolution of the pandemic in Africa.
The study was conducted across Cameroon's 10 regional capitals, between 2021 and 2022 as the country hosted a mass gathering.
We conducted a cross-sectional population-based survey in 2022, including SARS-CoV-2 seroprevalence testing and retrospective mortality estimation using two-stage cluster sampling. We estimated and compared seroprevalence and crude mortality rates (CMR) to a survey conducted in 2021 using the same methodology.
We performed serologic testing on 8400 individuals and collected mortality data from 22 314 individuals. Approximately 5% in each survey reported SARS-CoV-2-vaccination. Rapid diagnostic test-based seroprevalence increased from 11.2% (95% confidence interval [CI]: 10-12.5) to 59.8% (95% CI: 58.3-61.2) between 2021 and 2022, despite no increase in the proportion vaccinated. The CMR decreased from 0.17 to 0.06 deaths per 10 000 persons per day between 2021 and 2022. In 2022, no deaths were reportedly attributable to COVID-19 as compared to 17 deaths in 2021.
Over a 12-month period encompassing two waves of omicron variant SARS-CoV-2 and a mass gathering, SARS-CoV-2 seropositivity in Cameroon approached 60%, and deaths declined despite low vaccination coverage.
This study challenges the assumption that high immunisation coverage is the sole determinant of epidemic control in the African context and encourages policymakers to increasingly rely on local research when designing response strategies for more effective outbreak management.
关于严重急性呼吸综合征冠状病毒2（SARS-CoV-2）在非洲社区免疫力的演变知之甚少。
我们评估了2021年8月至2022年9月喀麦隆抗SARS-CoV-2抗体、死亡率和疫苗接种状况的变化，以开始描述非洲大流行的演变情况。
该研究于2021年至2022年期间在喀麦隆的10个地区首府进行，当时该国举办了一次大型集会。
我们在2022年进行了一项基于人群的横断面调查，包括SARS-CoV-2血清流行率检测和使用两阶段整群抽样的回顾性死亡率估计。我们使用相同方法将血清流行率和粗死亡率（CMR）与2021年进行的一项调查进行了估计和比较。
我们对8400人进行了血清学检测，并收集了22314人的死亡率数据。每次调查中约5%的人报告接种了SARS-CoV-2疫苗。尽管接种疫苗的比例没有增加，但基于快速诊断测试的血清流行率在2021年至2022年期间从11.2%（95%置信区间[CI]：10-12.5）增至59.8%（95%CI：58.3-61.2）。CMR在2021年至2022年期间从每10000人每天0.17例死亡降至0.06例死亡。2022年，据报告没有死亡病例归因于COVID-19，而2021年有17例死亡。
在包含两波奥密克戎变异株SARS-CoV-2和一次大型集会的12个月期间，喀麦隆的SARS-CoV-2血清阳性率接近60%，尽管疫苗接种覆盖率较低，但死亡人数有所下降。
本研究挑战了高免疫覆盖率是非洲背景下疫情控制唯一决定因素的假设，并鼓励政策制定者在设计应对策略以更有效地管理疫情时更多地依赖本地研究。
