COVID booster High school student shows barriers are better A US high school student has published a paper in PLOS ONE, suggesting that physical barriers are more effective than distancing to limit coronavirus spread. Atreyus A. Bhavsar, from Blake High School in Minneapolis, US, set up a series of experiments with mannequins, using balloons filled with fluorescent paint to mimic coughs and sneezes. When a balloon burst inside a mannequin’s mouth, droplets of paint flew out and patterned the mannequin’s surroundings. Some of the experiments had mannequins wearing masks, while others were set up to simulate Bhavsar’s high school cafeteria, where students have to take their masks off to eat.