For low- and middle-income countries, a COVID-19 vaccination program built on prompt procurement, effective on-the-ground distribution, and a rapid pace of vaccination (the total number of doses given daily) is likely to have a greater public health impact than one focused on relatively small differences in vaccine efficacy, according to a study led by researchers at Massachusetts General Hospital (MGH). Scientists evaluating clinical outcomes and cost-effectiveness of a COVID-19 vaccination program in South Africa found that an emphasis on these implementation factors in countries with limited resources is likely to dramatically reduce infections, save lives, and curtail overall health care costs through fewer hospitalizations. The study appears in Nature Communications.