The response of the scientific community to the global health emergency caused by the COVID-19 pandemic has produced an unprecedented number of manuscripts in a short period of time, the vast majority of which has been shared in the form of preprints posted before peer review on preprint repositories. This surge in preprint publications has in itself attracted considerable attention, although mostly in the bibliometric literature. In the present study we apply a mathematical growth model, known as the generalized Richards model, to describe the time evolution of the cumulative number of COVID-19 related preprints. This mathematical approach allows us to infer several important aspects concerning the underlying growth dynamics, such as its current stage and its possible evolution in the near future. We also analyze the rank-frequency distribution of preprints servers, ordered by the number of COVID-19 preprints they host, and find that it follows a power-law decay. This Zipf-like law indicates the presence of a cumulative advantage effect, whereby servers that already have more preprints receive more submissions.
Modelling the epidemic growth of preprints on COVID-19 and SARS-CoV-2