The secrets of people who never get sick

Some lucky folk claim to never get a cold or take days off work. Can we become more like them?Every now and then one pops up at work, down the pub, in the park, outside the school gate, or in your own family’s mythology. The person who claims never to get sick. Colds brush past them without leaving so much as a sniffle. They laugh in the flushed face of flu, spray hand sanitiser in the rheumy eyes of infection, and never take a day off work. They appear to be superhuman, with the kind of k