Ministry of Public Health, Littoral Regional Delegation, Douala, Cameroon.
International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul, 06800, Republic of Korea.
BMC Public Health. 2022 Oct 23;22(1):1956. doi: 10.1186/s12889-022-14328-w.
Immunization is an effective preventive health intervention. In Cameroon, the Expanded Program on Immunization (EPI) aims to vaccinate children under 5 years of age for free, but vaccination coverage has consistently remained below the national target. Vaccines are distributed based on the target population size, factoring in wastage norms. However, the vaccine wastage rate (VWR) may differ among various settings. Our study aimed to assess vaccine wastage for different site settings, seasonality, and vaccine types in comparison to vaccination coverage in order to provide comprehensive insights on vaccine wastage.
A retrospective data collection and analysis were conducted on immunization and vaccine wastage data in the Littoral Region of Cameroon during 2016 and 2017. Health districts were classified as urban or rural, seasonality was categorized as rainy or dry season, and vaccine types were grouped into liquid, lyophilized, oral, and injectable vaccines. VWRs and vaccination coverage rates (VCRs) were calculated, and the vaccine waste factor was investigated.
The VWR of Bacillus Calmette-Guérin (BCG; 32.19%) was the highest, followed by measles and rubella (MR; 19.05%) and yellow fever (YF; 18.34%) among all EPI vaccines in the Littoral Region of Cameroon during 2016 and 2017. Single-dose vaccine vials exhibited lower VWRs than multi-dose vials. Dry season was associated with higher VWRs for most vaccines, although more lyophilized vaccines (BCG, MR, YF vaccines) were wasted in rainy season in 2016. The VWR was persistently higher in rural than urban health districts. The months of February and November saw a decrease in VCRs. The study found an overall negative correlation between VCR and VWR.
Multiple factors may cause wastage of EPI vaccines in Cameroon. Vaccination area characteristics, seasonality, types of vaccines such as multi- or single-dose, lyophilized or injectable vaccines are related to VWRs in Littoral Region. Further research on vaccine wastage and vaccination coverage across Cameroon is needed to better understand the socio-behavioral aspect of vaccine in-take that may affect the level of vaccination and vaccine wastage. Public health system strengthening is warranted to adapt more real-time monitoring of the VWR and VCR for each vaccine in the government's immunization programs.
免疫接种是一种有效的预防保健干预措施。在喀麦隆，扩大免疫规划（EPI）旨在为 5 岁以下儿童免费接种疫苗，但接种覆盖率一直低于国家目标。疫苗的分发是根据目标人群规模进行的，同时考虑了损耗规范。然而，不同环境下的疫苗损耗率（VWR）可能有所不同。我们的研究旨在评估不同地点设置、季节性和疫苗类型的疫苗损耗情况，并与接种覆盖率进行比较，以便全面了解疫苗损耗情况。
对喀麦隆滨海地区 2016 年和 2017 年的免疫接种和疫苗损耗数据进行回顾性数据收集和分析。卫生区分为城市或农村，季节性分为雨季和旱季，疫苗类型分为液体、冻干、口服和注射疫苗。计算了疫苗损耗率（VWR）和疫苗接种覆盖率（VCR），并调查了疫苗浪费因素。
2016 年和 2017 年，喀麦隆滨海地区卡介苗（BCG；32.19%）的 VWR 最高，其次是麻疹和风疹（MR；19.05%）和黄热病（YF；18.34%）。单剂量疫苗小瓶的 VWR 低于多剂量小瓶。大多数疫苗在旱季的 VWR 较高，但在 2016 年，更多的冻干疫苗（BCG、MR、YF 疫苗）在雨季被浪费。农村卫生区的 VWR 持续高于城市卫生区。2 月和 11 月的 VCR 有所下降。研究发现 VCR 与 VWR 之间存在总体负相关。
多种因素可能导致喀麦隆 EPI 疫苗的浪费。接种区域特征、季节性、疫苗类型（多剂量或单剂量、冻干或注射疫苗）与滨海地区的 VWR 有关。需要对喀麦隆各地的疫苗浪费和接种覆盖率进行进一步研究，以更好地了解影响接种水平和疫苗浪费的疫苗摄入的社会行为方面。有必要加强公共卫生系统，以便更好地实时监测政府免疫规划中每种疫苗的 VWR 和 VCR。
