Moves by the U.S., Japan and others to mandate COVID-19 tests for passengers arriving from China reflect global concern that new variants could emerge in its ongoing explosive outbreak — and the government may not inform the rest of the world quickly enough.
There have been no reports of new variants to date. But given the country's track record, the worry is that China may not be sharing data on any signs of evolving strains that could spark fresh outbreaks elsewhere.
