Rene Nkenyi1, Se Eun Park2,3, Sunjoo Kang4, Gi Deok Pak5, Calvin Tonga6, Yun Chon5. 1. Ministry of Public Health, Littoral Regional Delegation, Douala, Cameroon. 2. International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul, 06800, Republic of Korea. SeEun.Park@ivi.int. 3. Yonsei University Graduate School of Public Health, 50-1 Yonsei-ro, Seodaemun-gu, 03722, Seoul, Republic of Korea. SeEun.Park@ivi.int. 4. Yonsei University Graduate School of Public Health, 50-1 Yonsei-ro, Seodaemun-gu, 03722, Seoul, Republic of Korea. ksj5139@hanmail.net. 5. International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul, 06800, Republic of Korea. 6. Ministry of Public Health, Surveillance, Monitoring & Evaluation Section, EPI Central Technical Group, Yaoundé, Cameroon.
Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Authors: Mohammad Naeem; Muhammad Zia Ul Islam Khan; Muhammad Adil; Syed Hussain Abbas; Muhammad Usman Khan; Ayasha Khan; Syeda Maria Naz Journal: J Ayub Med Coll Abbottabad Date: 2011 Jul-Sep