To understand why we need to distinguish between two kinds of aid. Traditional country lending seeks to improve outcomes in individual developing countries, while financing of global public goods (GPGs) aims to improve global welfare. The latter includes the development of technologies to promote agricultural productivity, actions to prevent climate change and mitigate its impact, knowledge creation, information provision, and, of course, preventing and dealing with pandemics.
Donors, therefore, need to decide how to allocate their funds between these two types of aid. Clearly, this decision should be informed by research regarding the relative effectiveness of country lending and financing of GPGs.
https://www.neweurope.eu/article/what-covid-19-means-for-international-aid-2/