Scientists from Johns Hopkins, Columbia and other leading American universities moved with rare speed when a Chinese virologist, Li-Meng Yan, published an explosive paper in September claiming that China had created the deadly coronavirus in a research lab.

The paper, the American scientists concluded, was deeply flawed. And a new online journal from MIT Press — created specifically to vet claims related to SARS-CoV-2 — reported Yan’s claims were “at times baseless and are not supported by the data” 10 days after she posted them.