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The rapid emergence in China of 2019-nCoV, a novel coronavirus, and its spread beyond its borders highlights the need for rapid scientific communication to better characterize transmissibility patterns, contagiousness, and illnesses and deaths caused by the pathogen.

Journals, of course, play a key role in disseminating peer-reviewed science, but their pace of publication takes time, which works against the rapid response required by a public health emergency.

In the world of medical publishing, something unusual happened this week. Editors of the New England Journal of Medicine described their policies about how the journal will treat manuscripts regarding the 2019-nCoV outbreak. As the co-founders of a preprint server, we were pleased that the editors “encouraged authors to submit their work for posting on preprint servers.” Of note, they also endorsed sharing data, sharing code, and communicating directly with public health authorities.


This move acknowledges the key role that preprints can play at a time when science is moving swiftly, especially when rapid information sharing and communication among researchers, policy makers, and public health advocates can save lives. Preprints are already doing that.

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Preprints are manuscripts describing research that has yet to undergo peer review. Preprint servers are online platforms dedicated to distributing these unreviewed scientific papers.


The advantages of preprints are that scientists can post them rapidly and receive feedback from their peers quickly, sometimes almost instantaneously. They also keep other scientists informed about what their colleagues are doing and build on that work. Preprints are archived in a way that they can be referenced and will always be available online. As the science evolves, newer versions of the paper can be posted, with older historical versions remaining available, including any associated comments made on them.

Preprints were originally developed so individuals in the physical sciences could share their work before peer review. The first such server was established in 1991 at the Los Alamos National Laboratory. It was later launched as arXiv, now hosted by Cornell University. It now has over one million preprints and receives in more than 10,000 submissions each month.

Preprint servers have spread throughout scientific fields and other fields, including clinical medicine. For life sciences information, bioRxiv is an example of an open access preprint server for the biological sciences. For the health sciences and clinical research, medRxiv (founded by Yale University, Cold Spring Harbor Laboratories, and the BMJ) and SSRN (a platform from the medical publisher Elsevier, which introduced “Preprints with The Lancet”) are options.

In an outbreak, research can produce prodigious amounts of information, and scientists around the world want to leverage what advances other have made, including learning from successes and failures (the latter typically take more time to publish). Researchers are using preprint servers to do this for the 2019-nCoV outbreak.

In medRxiv, a preprint from Lancaster Medical School, the University of Glasgow, and the University of Florida reported early estimations of predictions for the spread of 2019-nCoV. In a preprint from Hokkaido University and the Japan Science and Technology Agency, investigators described epidemiological characteristics of 2019-nCoV infection using publicly available case data. A preprint from the University of the Chinese Academy of Sciences, the Shenzhen Artificial Intelligence and Data Science Institute, the City University of Hong Kong, Peking University, and the Chinese PLA Center for Disease Control and Prevention reported that 2019-nCoV has a higher effective reproduction number than SARS, with a comparable fatality rate. Researchers from the Netherlands Centre of Infectious Disease Control and Leiden University Medical Center estimated the incubation period of 2019-nCoV. A team from Hokkaido University and the University of Oxford reported the value of using information to predict a novel pathogen in advance of virological testing.

On SSRN, researchers from the University of Malaya, the Asian Development Bank, Universiti Sains Malaysia, KUST, and Comstats Institute of Information Technology evaluated the economic impact of 2019-nCoV. In a preprint from Xi’an Jiaotong University, Shaanxi Normal University, and York University, investigators estimated the transmission risk of 2019-nCoV. Scientists with Wuhan Jinyintan Hospital and Shanghai Jiao Tong University described the epidemiological and clinical characteristics of 99 cases of 2019-nCoV.

In bioRxiv, there are already more than 20 preprints reporting studies of 2019-nCoV, including work on transmission dynamics, evolutionary and molecular analyses, and examining its origin in bats.

What is remarkable about these preprints is the diversity of institutions and the breadth of collaborations. Preprints are serving a critical role in fostering scientific communication and rapid awareness of others’ work, as was suggested by the New England Journal of Medicine.

That said, it’s important to realize that these contributions are works in progress and have not been peer reviewed, meaning they have not been scrutinized by researchers other than the authors, have not been revised in response to comments or suggestions from peer scientists and editors, and should not be relied on to guide clinicians or patients. Although the quality of these contributions vary, just as they do at scientific meetings, the earlier sharing of research holds the potential to accelerate progress.

Preprint servers have safeguards in place to protect the public’s interest. SSRN states that it checks each manuscript to ensure that it is part of “scholarly discourse.” It further checks on funding disclosures, conflicts of interest, and trial registration. medRxiv does the same, and screens contributions for information that would be harmful to the public’s health.

Peer review remains vitally important in the scientific ecosystem, but it often takes time. In the interim, it is valuable for scientists to share information with each other. They do that at major scientific meetings and local research conferences, but the timing of those meetings may not coincide with the production of new knowledge that needs to be shared. Preprint servers are like scientific meetings that are always in session, giving researchers consistent opportunities to share and receive feedback from the broad scientific community.

Experience with the Zika and Ebola outbreaks showed that preprints were frequently available three months or more before journal publication. In cases like these, and the previous coronavirus outbreaks of SARS and MERS, much of the research was not publicly accessible at the time it was most desperately needed.

In times of public health crises, researchers, public health experts, clinicians, and others need to work together and rapidly exchange information, provide constructive critiques and checks on claims, share data and code, and seek — above all — to put the public’s interest first.

Harlan M. Krumholz, M.D., is professor of medicine and of public health at the Yale School of Medicine, director of the Center for Outcomes Research and Evaluation at Yale New Haven Health System, and co-director of the Yale Open Data Access (YODA) Project. Theodora Bloom, Ph.D., is executive editor of The BMJ. Joseph S. Ross, M.D., is professor of medicine and of public health at the Yale School of Medicine, a member of the Center for Outcomes Research and Evaluation at Yale-New Haven Health System, and co-director of the YODA Project. They are three of the six co-founders of medRxiv.