Medical workers in Prince George’s County, Maryland, gave dozens of children ages 5-11 expired COVID-19 vaccines after they were mistakenly stored in the refrigerator with usable doses, the county health department says. There’s no health risk to the 70 children who received either their first or second dose of the Pfizer vaccine on Friday, Nov. 26 at the Prince George’s Sports and Learning Complex in Landover, but the expired doses are likely to be less effective, health officials said Thursday.