Ominous signs of a coronavirus backslide are piling up in the US. The American Academy of Pediatrics released new guidance yesterday recommending everyone over the age of 2 wear a mask while in school, regardless of vaccination status. That’s a stricter position than the one the CDC took earlier this month. One reason for the tighter precaution? Many school-aged children are not eligible for a Covid-19 vaccination yet, and recent virus surges have overwhelmingly affected unvaccinated people. The average of new daily cases in the US this week is up 66% from last week and 145% from three weeks ago.