A number of publishers and library vendors, while not opening up the entirety of their collection catalogs at this time, have elected to provide research and articles on the coronavirus/COVID-19. Below is a selection of that open content.
American Chemical Society - https://pubs.acs.org/page/vi/chemistry_coronavirus_research
American Institute of Physics - https://publishing.aip.org/publications/journals/covid-19/
Duke University Press - https://www.dukeupress.edu/Explore-Subjects/Syllabi/Navigating-Pandemic-Syllabus
Lexis Nexis - https://bis.lexisnexis.com/COVID-19
New England Journal of Medicine - https://www.nejm.org/coronavirus
Oxford University Press - https://academic.oup.com/journals/pages/coronavirus
Springer Nature - https://www.springernature.com/gp/researchers/campaigns/coronavirus
Brill - https://www2.brill.com/COVID-19_Collection (not an STM publisher, but Brill's open collection includes "books and articles on topics such as public health, distance learning, and crisis research.")
Duke UP is making available a selection of topical readings lists and associated content.