Table 4. Top 10 commented on COVID-19 preprints.

Rank	Source	DOI	Title	Posted date	Comments count
1	medRxiv	10.1101/2020.04.14.20062463	COVID-19 Antibody Seroprevalence in Santa Clara County, California	April 17, 2020	582
2	medRxiv	10.1101/2020.03.24.20042937	Correlation between universal BCG vaccination policy and reduced morbidity and mortality for COVID-19: an epidemiological study	March 28, 2020	149
3	bioRxiv	10.1101/2020.01.30.927871	Uncanny similarity of unique inserts in the 2019-nCoV spike protein to HIV-1 gp120 and Gag	January 31, 2020	129
4	medRxiv	10.1101/2020.04.16.20065920	Outcomes of hydroxychloroquine usage in United States veterans hospitalized with Covid-19	April 21, 2020	129
5	bioRxiv	10.1101/2020.04.29.069054	Spike mutation pipeline reveals the emergence of a more transmissible form of SARS-CoV-2	April 30, 2020	75
6	medRxiv	10.1101/2020.03.11.20031096	Relationship between the ABO Blood Group and the COVID-19 Susceptibility	March 16, 2020	72
7	medRxiv	10.1101/2020.03.27.20043752	Forecasting COVID-19 impact on hospital bed-days, ICU-days, ventilator-days and deaths by US state in the next 4 months	March 30, 2020	61
8	medRxiv	10.1101/2020.03.22.20040758	Efficacy of hydroxychloroquine in patients with COVID-19: results of a randomized clinical trial	March 30, 2020	58
9	medRxiv	10.1101/2020.04.16.20067835	Saliva is more sensitive for SARS-CoV-2 detection in COVID-19 patients than nasopharyngeal swabs	April 22, 2020	56
10	medRxiv	10.1101/2020.04.05.20054361	Population-level COVID-19 mortality risk for non-elderly individuals overall and for non-elderly individuals without underlying diseases in pandemic epicenters	April 8, 2020	53

COVID-19, Coronavirus Disease 2019.