As healthcare workers in the US began lining up for their first coronavirus vaccines on 14 December, Esmeralda Campos-Loredo was already fighting for oxygen. The 49-year-old nursing assistant and mother of two had started having breathing problems just days earlier. By the time the first of her co-workers were getting shots, she was shivering in a tent in the parking lot of a Los Angeles hospital, because no medical beds were available. When she...