Compared to Zaire ebolavirus (ZEBOV) in 2014 and Zika virus (ZIKV) in 2015 as the most recent globally significant outbreaks of emerging viruses, preprint responses to the COVID-19 outbreak have been enormously accelerated (Figure 2), increasing at approximately a hundred-fold and forty-fold higher rates, respectively. While an estimated 11.9 COVID-19 preprints have been posted per day, during the ZEBOV epidemic, relevant preprints were posted only once every 10.5 days (Table 1). Preprint responses to COVID-19 also initiated much earlier; no preprints addressing ZEBOV and ZIKV were posted on the examined servers until over six months after the first cluster notification.