Preprints are original research manuscripts which have been shared prior to undergoing peer review. Preprints are typically shared on a preprint archive.
Preprints first arose in the late 20th century in scientific fields such as physics and mathematics. For many years, human-focused disciplines, such as health sciences, were wary of preprints. However, over the last five years, this has shifted significantly. Changes began in 2017 with the National Institutes of Health (NIH) encouraging researchers to share interim research products funded by the NIH via repositories such as preprint servers. In 2019, the first explicitly health sciences focused preprint server was launched: medRxiv. Then COVID-19 hit, sending a wave of articles to preprint servers including medRxiv.
Preprints are now an important component of the research landscape in the health sciences. As a result, searching preprint servers is now an important component of a comprehensive review of unpublished literature on health sciences topics.