Tracing the origin of SARS-CoV-2 in bats leads to a stark warning

Scientists pinning down the evolutionary history of the virus that causes Covid-19 conclude that it’s been circulating in bats for decades, dating its divergence from other bat viruses to as early as 1948. Diverse viruses can recombine in bats, they write, defying attempts to pick out the ones that could cause human outbreaks before they emerge. That places the burden back on human surveillance systems designed to spot, identify, and classify dangerous viruses once they show up in people — in real time.

Other pandemic developments:

• A new federal report acquired by the New York Times found that the number of states experiencing Covid-19 outbreaks serious enough to place them in the “red zone” had grown to 21; it urged officials in those states to impose more restrictions.
• One of the nation’s largest teachers unions is authorizing its members to strike if their schools plan to reopen without proper safety measures in the middle of the global pandemic, AP reports.
• Responding to concerns over access to medicines that were hatched with U.S. taxpayer funds, Democratic lawmakers called on the Government Accountability Office to investigate the discovery and development of remdesivir, the first drug authorized to treat Covid-19, STAT’s Ed Silverman notes.