The impact of COVID-19 stringency policies on primary health care in Cameroon: a case study of the expanded program of immunisation

Background The COVID-19 pandemic and containment policies disrupted health services, including vaccination activities in Cameroon since March 2020. This study evaluates the impact of COVID-19 on the Expanded Programme of Immunisation (EPI) in the Littoral region of Cameroon. Methods A cross-sectional study used secondary data from Cameroon’s District Health Information System-2, from the COVID-19 situational report, and from the international data platform on contingency measures. Time series analysis of monthly vaccination data (BCG, PENTA 1 and 3, measles) compared Pre-COVID (Jan 2019-Feb 2020) and COVID periods (Mar 2020-Dec 2021). Bivariate analysis with simple linear regression assessed the association between COVID-19 cases stringency index, and vaccination coverages. The Wilcoxon rank sum test compared vaccination coverage changes between rural and urban districts. Results Vaccination coverage increased initially right after the start of the pandemic, but dropped over the following 10 months. There was a weak, non-significant negative association between COVID-19 cases/stringency index and vaccination coverages. BCG coverage dropped by 4.75% (P=0.3), while PENTA1, PENTA3, and measles coverages dropped significantly by 7.83% (P=0.04), 9.55% (P=0.002), and 12.11% (P=0.001), respectively. Rural areas, despite having fewer COVID-19 cases, saw a more pronounced decline in EPI coverage than urban areas, suggesting additional influencing factors. Conclusions The COVID-19 pandemic led to significant declines in PENTA1, PENTA3, and measles vaccination coverage in the Littoral region of Cameroon, especially in rural areas. While other studies showed that these declines were due to the COVID-19 pandemic, our study showed that factors beyond COVID-19 cases and stringency measures influenced vaccination rates. There is therefore a need to do further studies to identify some of these factors to strengthen health systems and to maintain immunisation services during future health crises.