As well as having a jab, there are other ways you can lower your chance of catching an infection. Washing your hands regularly is vital – do it with soap for at least 20 seconds, no less than five times a day. There’s some evidence that taking vitamin C in high doses can shorten the symptoms of flu, but no direct evidence that it can stop you from getting it. However, US scientists at the University of Florida found that people who drank cranberry juice every day suffered fewer cold and flu symptoms. Other research suggests that taking vitamin D supplements could help fend off the lurgies.