*2.3. Sampling and Data Collection*

Based on administrative data, the Littoral Region, with 32,995 COVID-19 cases representing 28.27% of national cumulative cases, and the Centre Region, with 36,506 COVID-19 cases representing 31.28% of national cumulative cases, were considered COVID-19 hotspot regions, and were included in the study. The secondary data on annual district DTP-1 and DTP-3 coverages in all districts in the two hotspot regions were extracted from DHIS-2 and prepared for analysis. A total of 56 of 189 health districts (29.6%) in Cameroon were included in the study, notably 24 from the Littoral Region and 32 from the Centre Region.
