Wellcome and Nature are among organisations to call for Coronavirus content to be shared openly. A number of publishers have made content available - they are listed by Wellcome at: https://wellcome.ac.uk/press-release/publishers-make-coronavirus-covid-19-content-freely-available-and-reusable and by STM at: www.stm-assoc.org/about-the-industry/coronavirus-2019-ncov. Some of the main publishers and their coronavirus free content are listed below. Many publishers have also committed to make content available through PubMedCentral.
AMBOSS Learning Card
BMJ online CPD: https://new-learning.bmj.com/covid-19
The Royal Society
Springer Nature (Springer, Nature, Scientific American, BMC)
Taylor and Francis Group
Wiley Online Library