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New lab tool spotlights mutation that speeds spread of Delta variant

As the world has learned to its cost, the Delta variant of the pandemic coronavirus is more than twice as infectious as previous strains. Just what drives Delta’s ability to spread so rapidly hasn’t been clear, however. Now, a new lab strategy that makes it possible to quickly and safely study the effects of mutations in SARS-CoV-2 variants has delivered one answer: a little-noticed mutation in Delta that allows the virus to stuff more of its genetic code into host cells, thus boosting the chances that each infected cell will spread the virus to another cell.

When are masks most useful? COVID cases offer... Nature - Masks offer the greatest protection indoors and during long exposures to people infected with the coronavirus — but other public-health measures matter, too. Remmel, Ariana nature

An analysis of hundreds of COVID-19 cases suggests that face masks are most protective in specific circumstances, such as exposure to a person with COVID-19 that lasts for more than three hours or that takes place indoors¹.