Sub Directorate of Vaccination, Ministry of Public Health, Yaoundé, Cameroon.
Sub Directorate of Vaccination, Ministry of Public Health, Yaoundé, Cameroon.
Vaccine. 2021 Feb 22;39(8):1290-1296. doi: 10.1016/j.vaccine.2021.01.017. Epub 2021 Jan 23.
Cameroon chose Oral Cholera Vaccine (OCV) mass vaccination campaign in addition to other interventions to respond to outbreaks since 2015. There is still a persistent controversy on the effectiveness of reactive OCV mass vaccination campaign.
This article aimed to share evidence-based observations on the effect of a reactive single-dose OCV mass vaccination campaign on cholera cases in Cameroon.
Health area centered risk analysis was used to identify nine high risk health areas among four health districts in the |North Region as hotspots. About 537,274 people at risk of cholera transmission one year of age and above including pregnant women were eligible to receive OCV. A total of 537,279 doses of OCV was deployed for vaccination from August 1-5, 2019 through door-to-door strategy for urban health districts, and fixed/ temporary fixed posts strategies for rural health districts.
The overall vaccination coverage was 99.9%. Vaccine wastage rate was less than 0.5% (0.0011%). Independent monitoring showed vaccination coverage at 97.2%. The 2019 epidemic curve went down after OCV intervention on the contrary to that in the year 2018 at the same period. After OCV intervention, cholera cases dropped from about 10.5 to 9.3 cases per week at the regional level while at the district level, they dropped from 5.3 to 2.1, 2.2 to 1.7, 0.6 to 0 and 1.7 to 1.5 cases per week respectively for Garoua, Garoua II, Tchollire and Pitoa. Though not statistically significant (p = 1.4, α = 0.05), cases per 1000 population seemed to remain unchanged among OCV zones (0.32/1000) and non-OCV zones (0.31/1000) in 2018 while they increased from 0.37 (OCV zones) to 0.53 (non-0CV zones) cases per 1000 population in 2019.
There might have been a general trend in the reduction of the number of new cases after a reactive single-dose OCV campaign.
自 2015 年以来，喀麦隆除了采取其他干预措施外，还选择了口服霍乱疫苗（OCV）大规模疫苗接种活动来应对疫情爆发。对于反应性大规模 OCV 疫苗接种活动的有效性仍存在持续争议。
本文旨在分享有关喀麦隆单次反应性 OCV 大规模疫苗接种活动对霍乱病例影响的基于证据的观察结果。
采用以卫生区为中心的风险分析方法，在北部地区的四个卫生区中确定了九个高风险卫生区作为热点地区。大约有 537,274 名年龄在 1 岁及以上且有感染霍乱风险的人，包括孕妇，有资格接受 OCV 接种。2019 年 8 月 1 日至 5 日，通过上门接种策略为城市卫生区，以及固定/临时固定接种点策略为农村卫生区，共部署了 537,279 剂 OCV。
总体接种覆盖率为 99.9%。疫苗浪费率低于 0.5%（0.0011%）。独立监测显示接种覆盖率为 97.2%。OCV 干预后，2019 年的疫情曲线下降，而同期 2018 年的疫情曲线上升。OCV 干预后，霍乱病例从地区层面每周约 10.5 例降至 9.3 例，而在区层面，每周分别从 5.3 例降至 2.1 例、2.2 例降至 1.7 例、0.6 例降至 0 例和 1.7 例降至 1.5 例，分别为加鲁阿、加鲁阿二世、乔利雷和皮托阿。虽然没有统计学意义（p=1.4，α=0.05），但 2018 年 OCV 区（每千人 0.32/1000）和非 OCV 区（每千人 0.31/1000）的每千人人口病例似乎保持不变，而 2019 年则从 OCV 区的每千人 0.37 例增加到非 OCV 区的每千人 0.53 例。
在进行单次反应性 OCV 疫苗接种活动后，新病例数量可能呈总体减少趋势。
