The study estimates that the economic recessions of 2020 could lead to around 300,000 additional deaths in children under five in low and middle-income countries. A 5% reduction in GDP per capita may cause 282,996 extra deaths, with higher reductions leading to even more losses. Sub-Saharan Africa is expected to bear nearly half of these potential deaths. The findings suggest that national income closely relates to child mortality rates in developing countries, and without adequate COVID-19 vaccination or herd immunity, similar trends in child mortality may continue in the coming years.